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PILATES FOR POSTURAL STABILITY IN COMPUTER USERS
BY
LANA STRYDOM
SUBMITTED IN FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MAGISTER ARTIUM IN THE FACULTY OF HEALTH SCIENCE AT THE NELSON
MANDELA METROPOLITAN UNIVERSITY.
December 2008
SUPERVISOR: DR. M L BAARD
CO-SUPERVISOR: MR. P E OLIVIER
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CHAPTER 1: PROBLEM IDENTIFICATION
1.1. Introduction
1.2. Problem Clarification
1.3. Problem Statement
1.4. Aim of the Study
1.5. Objectives of the Study
1.6. Methodology
1.7. Limitations of the Study
1.8. Significance of the Study
1.1 INTRODUCTION
The impact of computer use is evident in every day life (Harrington, Carter, Birrell and
Gompertz, 2000:264). Lind (2002:18) explains that global trends continue to show that the
most severe work-related health problems that exist amongst computer users are
musculoskeletal disorders. As technology has lead to increases in automation, so it has lead
to increases in work-related illnesses.
Although studies have explored the effects of ergonomics (Thibodeau, 1995:322) in static
working positions there has been little evidence supporting a solution in overcoming poor
occupational postures. Many health practitioners argue that occupationally caused, or
aggravated, musculoskeletal disorders are steadily increasing. Thus, even though computers
have improved productivity and made work easier for the population in general, they have
adverse effects as well. Designing the proper tools or a setup of the work place is of prime
importance for the elimination of chronic diseases attributed to sedentary lifestyles.
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Regular physical activity had long been regarded as an important component of a healthy
lifestyle. This notion has recently been reinforced by scientific evidence linking regular
physical activity with a wide array of physical and mental health benefits, synonymous with an
improvement in wellness (Pratt, Macera, and Wang, 2000:63). According to Pratt et al.
(2000:63) higher direct medical costs associates with physical inactivity.
Further cross-sectional epidemiologic studies and controlled experimental investigations
conducted by Okura, Nakata and Tanaka (2003:1131) had demonstrated that physically
active adults, in contrast to their sedentary counterparts, tend to develop and maintain higher
levels of physical fitness. These studies had not only demonstrated the positive results of
physical activity, such as an improvement in blood lipid profile, body composition, glucose
tolerance and insulin sensitivity, but had also shown that participation in such activity
decreased the risk of developing several chronic hypokinetic diseases, including coronary
heart disease (CHD), hypertension, non-insulin dependant diabetes mellitus (type II),
osteoporosis, colon cancer, anxiety and depression. In addition, low levels of habitual
physical activity and the subsequent low levels of physical fitness were associated with a
marked increase in all-cause mortality rates. Okura et al. (2003:1131) confirm that effects of
exercise intensity on physical fitness and risk factors for coronary Herat disease.
1.2. PROBLEM CLARIFICATION
The advancement of electronic technology and proliferation of computer use has resulted in a
variety of work-related neck, lower back, hand, arm and wrist injuries in computer operators
(Evans and Patterson, 2000:35). According to Deyo (1998:49) work disability related to back
pain has risen steadily, despite economics being increasingly post-industrial with a reduction
in manual labour.
Sedentary occupations lend themselves to computer use which is a constant risk factor for
the development of lower back pain (Cartas, Nordin, Frankel, Malgady and Sheikhzadeh,
1993:603; Lengsfeld, Frank, van Deursen and Griss, 2000:665; Videman, Nurminen and
Troup, 1990:728). According to Van Vuuren, van Heerden, Becker, Zinzen and Meeusen
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(1991:2) lower back problems constitute one of the most challenging medical problems in
industrial countries. Lower back pain affects 58 – 84% of all adults at some point in their life
and place a significant burden on health services internationally (Goubert, Crombez, De
Bourdeaudhuij, 2004:390).
A growing number of studies have also suggested that people with lower back pain may have
deficits in postural coordination, such as deficits in the coordination of whole-body voluntary
movements (Cacciatore, Horak and Henry, 2005:565). Poor seated posture is often
exaggerated by poorly designed workstations that offer little movement for the employee to
adjust or adapt him or herself. Occupational postures such as sitting at a desk and standing
during lunch breaks have an effect on postural stability. Anderson and Ortengren cited in
Kayis and Hoang (1999:255) stated that during sitting, the activity of the back muscles is
similar to that during standing, but in supported sitting, as with the elbows resting on the
knees, there is no activity in the lumbar back muscles. Following appropriate postural training
(both static and dynamic), the patient or employee can take responsibility for the management
of pain that results from chronic postural strain and many activities of daily living (Travell and
Simmons, 1983:548).
The American College of Sport Medicine (ACSM) advised individuals to engage in aerobic
activity for 20-60 minutes, three to five days a week with latest documented research Pate,
Pratt, Blair, Haskell, Macera, Bouchard, Buchner, Ettinger, Heath, King (1995:402). Prat et al.
(1995:403) advising structured physical activity in adults to be performed for an accumulated
30 minutes or more of moderate-intensity physical activity on most, preferably all, days of the
week. The same author went on to establish that although the earlier exercise
recommendations were based on documented improvements in fitness, they provide most of
the disease prevention benefits associated with an increase in physical activity. Majority of
these benefits could be gained by performing moderate-intensity physical activities outside of
formal conventional exercise programmes that has particular relevance to Pilates intervention.
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Decline in flexibility has been associated with a decline in functional ability, therefore aiding to
the advancement of hypokinetic disease states, such as chronic low back pain and
debilitating associated wellness. Flexibility represents the ability to move a joint through its full
range of motion (ROM) and is one of the key principles in the design of a Pilates programme.
Dynamic stabilization according to Brukner and Khan (2007:158) refers to the ability to utilize
strength and endurance in a functional manner throughout all planes of motion despite
changes in the centre of gravity. This component has specific relevance to Pilates exercise
programme design for postural awareness education. There is a lack of documented
evidence pertaining to the efficacy of functional core strengthening exercises. Randomized
controlled trials have been scarcely documented on the efficacy of core such strengthening
programmes. Brukner and Khan (2007:1670) state that most studies have been prospective
and of uncontrolled case series study design. According to Graf, Guggenbühl and Krueger
(1998:81) back disorders and discomfort are major sources of lost work time and worker
dissatisfaction.
Work place layout, working postures and working technique has so far been poorly
researched. General conclusions have only recently started to influence ergonomics. Studies
have focused on work-related lower back disorders which has resulted in work absence
among the employed and found it to be common as well as expensive to alleviate. Financial
costs, accrued due to reduced productivity, sick leave, work disability, and the use of medical
services, related to hand, arm, shoulder, and neck injuries are considerable (Ijmker, Blatter,
Van der Beek, Van Mechelen and Bongers, 2006:214). According to Wynne-Jones, Dunn and
Main (2006:1) the cost of lower back pain to employers is high, with an estimated £9090
million lost in the United Kingdom in1998. Researchers, such as Johanning (2000:94); Pope,
Goh and Magnusson, (2002:50); Zinzen (2002:41) and Deyo (1998:49), focus on lower back
pain and work-related poor postural awareness and control.
Physical exercise has the potential to reduce work-related musculoskeletal stress, both
immediately and over a long-term period. Accumulating evidence indicates that physical
activity and structured exercise help maintain an independent life by maintaining postural
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stability, strength, endurance, bone density and functional ability (Skelton, 2001:33). Physical
exercise programmes have been adopted and used successfully in many oriental countries
such as China, Japan and Korea (Ylinen, Takala, Nykanen, Hakkinen, Malkia, Pohjolainen,
Karppi, Kautiainen and Airaksinen, 2003:2509; Tsauo, Lee, Hsu, Chen and Chen, 2004:254;
Takala, Viikari-Juntura and Tynkkynen, 1994:17).
Research has shown that Pilates-based exercise improves torso- or core strength and offers
other benefits including spinal and joint mobility, proprioception, balance, and coordination.
Cassity (2004:86) reiterates that the use of Pilates as a method of training could enhance
biomechanical functioning of the body, balance, co-ordination, postural and spatial
awareness, strength and flexibility. Pilates-based exercise is increasing in popularity as a
general and clinical exercise training technique. Although Pilates has been practiced for
almost a decade, there is a limited amount of sound research on Pilates being used as an
intervention method to combat musculoskeletal disorders. Many health care professionals are
only recently starting to refer patients to certified Pilates instructors for specialized exercise
programmes to address postural awareness and education, as well as rehabilitation
purposes.
For the purpose of this study the Biodex Stability System (950-304) was used to measure the
postural stability of the participants. The Biodex Stability System challenges a participants’
balance while standing on a movable platform that tilts to a maximum of 20 degrees in
different directions. According to The Biodex Service/Operation Manual (2000:1-2) using this
unique device, clinicians can assess neuromuscular control by quantifying the ability to
maintain dynamic bilateral and unilateral postural stability on a static or unstable surface. The
system uses a mechanical system which ranges from level one to level eight, one
representing the greatest instability. The Biodex Stability System was shown to be reliable in
studies (Hinman, 2000:249 and Aydoğ, Aydoğ, Cakci and Doral, 2006:1).
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1.3. PROBLEM STATEMENT
In this study computer users were selected due to the fact that there has been a high
incidence of employees and employers who experience discomfort when sitting for prolonged
periods of time. Any prolonged posture will lead to static loading of the soft tissues and cause
discomfort (Pope et al. 2002:49) Pilates can be used to improve muscular symmetry and in
turn aid in the adjustment of musculature imbalances while seated for extended amounts of
time. Learning to use the body correctly and working in alignment helps to achieve greater
muscular symmetry because postural imbalances are rectified (Kimberly and Katherine Corp,
2002:2).
Given the widespread use of computers, it may be more appropriate now than ever before to
consider specific exercises that could be performed at home or at the workstation to relieve
musculoskeletal discomfort resulting from sedentary work.
1.4. AIM OF THE STUDY
The purpose of this study was to determine the impact of a Pilates training programme on the
postural stability of sedentary adult computer users in the workplace.
1.5. OBJECTIVES OF THE STUDY
In order to address the aim of the study the following objectives prior to and after the eight
week Pilates intervention programme, were set and explored; to assess and describe the
overall postural indexes, to assess and describe the anterior-posterior postural indexes, to
assess and describe the medial-lateral postural indexes.
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1.6. METHODOLOGY
This study employed an exploratory, descriptive quasi-experimental approach which uses
quantitative data collected through a pre- and posttest statistical analysis completed by
computer users in the Nelson Mandela Metropole. The computer users were selected using
non-probability convenience sampling. Volunteers were obtained by means of convenience-
and snowball sampling in which participants already involved in the study found other
participants relevant to the study. The sample included male and female computer users; the
age range of the participants was 25 to 59- years. The reason for choosing a wide sample of
age ranges was that Pilates can be applied to and benefits can be derived from any age.
An inclusion criterion was that the participants must have been sedentary and been using a
computer for at least three years. Mahler, Froelicher, Miller & York (1995:18) cited in Whaley,
Armstrong, Brubaker and Otto (2005) clarify that a sedentary lifestyle or physical inactive
identified person is one who does not participate in 30 minutes of continuous or intermittent
physical activity for a minimum of three days a week.
1.7. LIMITATIONS OF THE STUDY
The first limitation of this study was the small sample size. Teaching Pilates exercises to a
large group would have negatively affected the reliability of the study. Due to the complex
nature of Pilates’ exercises it is extremely important for the instructor to provide individual
attention at all times during the one hour class.
It was not possible to include intermediate or advanced exercises from the Pilates repertoire,
which could have influenced the results, as the variety of somatotypes of the participants
prohibited progression from a beginner level to a higher level of performance. Due to the
diverse nature of computer users in the Nelson Mandela Metropole and the volunteer
dependency of the sample, it was not possible to select a more homogenous age range for
the participants. The wide range in variance could have diluted the significance of the results
obtained.
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1.8. SUMMARY
The study explored the proposition that sedentary computer users in the workplace could
prevent debilitating musculoskeletal problems due to poor working postures by participation in
a regular mat-based Pilates intervention programme.
For the purpose of this treatise, literature pertaining to ergonomics and work-related injuries,
postural stability and the Pilates method as intervention strategy to train postural stability, will
form the core body of evidence as the study furthermore unfolds.
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CHAPTER 2: LITERATURE REVIEW
2.1. Introduction
2.2. Ergonomics and Work-Related Injuries
2.3. Lower-Back Pain
2.4. Posture
2.5. Postural Stability
2.6. Physical Exercise as an Intervention for both Mind and Body
2.7. The Pilates Method as Intervention Strategy to Train Postural Stability
2.8. Summary
2.1. INTRODUCTION
Computers and visual display terminals are frequently used by sales personnel, managers,
engineers and technical workers. Use of computers and video display terminals in workplaces
has increased dramatically during the last two decades (Waikar and Bradshaw, 1995:16). The
Occupational Safety and Health Administration, cited in Waikar and Bradshaw (1995:16),
confirmed that presently there may be as many as 80 million visual display terminals in the
workplace.
In many countries, the widespread use of computers has led to considerable media attention
concerning potential adverse health effects (Ijmker et al. 2006:212). The advancement of
electronic technology and the proliferation of computer use have resulted in a variety of work-
related neck, lower back, hand, arm and wrist injuries in computer operators (Evans and
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Patterson, 2000:35). Sudol-Szopińska (2006:263) states that the dynamic growth of new
workplaces associated with the introduction of modern technologies has increased the
frequency of many health problems over the recent years. Technology has rapidly and
profoundly changed the manner in which office work is done and the work settings needed to
support it. According to Kaplan and Aronoff (1996:6) technology has also highlighted how the
office environment affects occupants’ health and productivity. The phenomenon has raised
public consciousness about ergonomics and the study of how humans interact with their
physical work environment. Health problems, such as carpel tunnel syndrome, cumulative
trauma disorders, and repetitive strain injuries; caused by inadequate design of the workplace
environment has decreased originally anticipated levels of office productivity (Attaran and
Wargo, 1999:92).
In this technological age the impact of computer use is evident in every day life (Harrington et
al. 2000:264). In addition, the financial costs, accrued due to reduced productivity, sick leave,
work disability, and the use of medical services, related to hand, arm, shoulder, and neck are
considerable (Ijmker et al. 2006:214). Accordint to Budnick, cited in Lucas (2007:2), Verizon,
a leading call centre in the United States of America, purchased ergonomic workplace plans
in pursuit of controlling absenteeism and turnover. According to Croasmum (2004:1)
everything from new tools and equipment to modified schedules are being implemented to
keep the rising absenteeism rates at bay in a countries long known for its rigorous work ethic.
The proliferating use of computers in the workplace, to substitute to manual tasks, results in
jobs becoming progressively more sedentary. Attaran and Wargo (1990:92) confirm that
employees are moving around less as they work. Holding the upper body still in an upright
position requires a lot of muscular effort and contributes to what is called a static load. Any
prolonged posture will lead to static loading of the soft tissues and cause discomfort (Pope et
al. 2002:49). Static working positions and poor postures are both associated with the
development of musculoskeletal disorders and discomfort (Graf et al. 1998:81). A study
conducted by Marcus, Gerr, Monteilh, Oritz, Gentry, Cohen, Edwards, Ensor and Kleinbaum
(2002:236) emphasized that the risk of musculoskeletal pain may be reduced by encouraging
specific seated postures. As far as the lumbar spine is concerned, a good posture is one in
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which the spine is towards the mid-point of its range of movement and the trunk is
unconstrained (i.e. free to move anteriorly and posteriorly), (Karwowski, 2006:469). Selby and
Triano (2006:1) confirm that posture is important for sitting in office chairs and at a
workstation. The same authors explain that by adopting a user-friendly workstation, which
includes proper adjustments of the office chair, computer and desk positioning, functional
postures will be prevalent. According to Fujimaki and Mitsuya (2002:17) the advantages of the
reclining posture result in reduced seat pan pressure, prolonged sitting posture that can be
maintained over time, and reduced fatigue of the upper body.
Pilates can be used to improve muscular symmetry and in turn aid in the adjustment of
musculature imbalances while sitting for extended amounts of time. Learning to use the body
correctly and working in alignment helps to achieve greater muscular symmetry because your
imbalances are rectified (Kimberly and Katherine Corp, 2002:2). Named after its creator,
Joseph Pilates, Pilates is a method of exercise that focuses on strengthening the core, which
consists of the abdominal and back musculature of the body. According to Giusti (2003:1)
Pilates aims to improve flexibility and strength through mat and machine exercises that
involve a series of stretches and controlled movements. It is purported to improve postural
awareness with a large focus on facilitating movement and re-education, however, there is
limited research to support this (Kaesler, Mellifont, Swete Kelly and Taaffe, 2007:1).
Considered one of the fastest growing forms of exercise in the world Joseph Pilates believed
his method could improve posture and alignment, while improving strength without bulking
(Crews, 2006:58). Pilates-inspired exercise is increasing in popularity as a general and
clinical exercise training technique (Kaesler et al, 2007:1). Solie (2007:19) confirms that
Pilates is a method of mind-body conditioning that improves body awareness, posture and
flexibility. Assuming a bent over posture at your desk for prolonged amounts of time will
inevitably affect our posture. Being seated for most of the day places great stress on
musculoskeletal structures, particularly the spine, and habitual problems with posture occur
because of the constant load on deep supporting muscles (Solie, 2007:19).
Kryzanowska, cited in Davis (2007:103), described Pilates as being a way of life. The use of
Joseph Pilates’ principles in life will influence the posture you assume when sitting or walking.
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(Davis, 2007:103). Grimes, cited in Davis (2007:103), confirmed that all Pilates exercises, as
strange as they may seem, are based on everyday movement.
The following chapters will describe and further explain the relationships between the role of
ergonomics, lower back pain, postural difficulties, postural stability and lastly how the Pilates
method can possibly play a role in the augmentation, resolution and improvement of these
issues.
2.2. ERGONOMICS AND WORK-RELATED INJURIES
In the 21st century individuals spend many hours working on PCs, laptops, and telephones
creating the risk for the development of musculoskeletal disorders (Lind, 2002:18).
Thibodeau, (1995:322) confirmed that “Desk Jockeys” suffer from aching backs, stiff necks,
and poor posture. He continues to illustrate that health care costs of ergonomic injuries are a
growing concern to employers. Thibodeau (1995:322) believed that the human body is not
designed to be immobile or to perform repetitive movements for hours on end. According to
Waikar and Bradshaw (1995:16) working with computers and/or visual display terminals
constituents as sedentary work. This type of work lends itself to constrained postures which
impart static loads on the neck, back, shoulders and upper extremities (Waikar and
Bradshaw, 1995:16). Sjogaard (1990:1) states that because there is insufficient research on
poor posture in the workplace, the result will manifest in the form of a syndrome of pain and
injuries.
Literature identifies several disorders as a result of chronic occupational computer usage to
indicate symptoms in the neck, shoulders, arms, hands or wrists. Gerr, Marcus & Monteilh
(2004:1) report that computer users are at increased risk of upper extremity musculoskeletal
disorders. According to the same authors early studies often found elevated rates of
musculoskeletal disorders among keyboard users when compared to non-users.
Jonai, Villanueva, Takata, Sotoyama and Saito (2001:219) indicate that not only is there an
increase in workload, but also increased pressure to meet deadlines in a technological
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market. This could lead to employees spending greater amounts of time engaged in computer
usage. Constrained posture and higher neck muscle activities have been reported among
users of notebook computers. Cole, Ibrahim, and Shannon (2005:1233) conclude that
performing biomechanical/physical tasks, such as organizing the workstation and
psychosocial stressors at work are among the causes of work-related cumulative trauma
disorders and repetitive strain injury.
According to the Bernard (1997:10) of the National Institute of Occupational Safety and
Health (NIOSH) in the United States of America links between computer use and a number of
symptoms, including pain in the hand, wrist, arm, neck, shoulders and lower back as well as
eye strain and headache, are well established. Delleman and Dul (2002:341) states that
injuries of this nature should be viewed as a potential source of strain on health services,
morbidity, disability and decreased earnings. Furthermore work-related musculoskeletal
complaints and disorders are a major cause of sick leave and disability (Delleman and Dul,
2002:341).
Sudol-Szopińska (2006:263) states that prolonged sitting may lead to numerous general
complications such as fatigue or discomfort, but also more specifically diseases of the
musculoskeletal system (the spine and upper limbs), deep vein thrombosis, as well as obesity
and its health-related consequences. Physical risk factors, such as prolonged sitting and neck
flexion have been identified as predictive of neck pain in the study of a mixed population of
workers from various industries, health and professional settings (Ariëns, Bongers,
Hoogendoorn, Houtman, Van Der Wal and Van Mechelen, 2001:1896). According to Hush,
Maher and Refshauge (2006:81) these and other physical factors, such as posture and neck
muscle endurance have not been prospectively investigated specifically in office workers.
Global trends show that the most severe work-related health problems that exist amongst
computer users are musculoskeletal disorders (Lind, 2002:18). Hadler, cited in
Gangopadhyay, Bharadwaj, Das and Ghoshal (2005:2), concurs that musculoskeletal
disorders are the most common self-reported work related illness. There is a profound
increase of risk factors involving long-time computer usage, as documented by Bishu,
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Hallbeck, Riley and Stenz (1991:90). The same authors conclude that sitting for prolonged
periods of time, performing repetitive motions and assuming poor postures will result in
musculoskeletal disorders. Hadler, cited in Gangopadhyay et al. (2005:2), explains further
that these reported work-related injuries generally cause excess stress on muscles,
ligaments, tendons, nerves and blood vessels as a result from prolonged sitting.
As technology has lead to increases in automation, so it has lead too increases in work-
related illnesses. This is evident by the tremendous rise in cumulative trauma disorders; the
fastest growing category of workplace trauma (Rowan and Wright, 1994:7). Graf et al.
(1998:81) propose that static working positions and poor postures are both associated with
musculoskeletal-disorders and discomfort. Rowan and Wright (1994:7) noted that cumulative
trauma disorders, which are musculoskeletal and nervous system injuries, result from
repeated exposure to micro-traumas rather than a single traumatic event.
Travers (1992:129) defines cumulative trauma disorders as a class of musculoskeletal
disorders of tendons, tendon sheaths, muscles, and related nerves and bones of the hands,
wrists, elbows, shoulders, neck, and back that are caused or aggravated by repeated
exertions and movements of the body. Sauter, Schleifer, Knutson (991:151), identified risk
factors associated with cumulative trauma disorder as, repetition of motion, extremes in joint
position, prolonged constrained posture, mechanical pressure points, and vibration. Grant and
Brophy (1994:1) specifically mention the impact of certain prolonged, non-neutral positions of
the joints that might stretch, compress, or otherwise stress tendons, nerves, or other soft
tissue, on the incidence of cumulative trauma disorders in the office. Thibodeau (1995:322)
identified the following factors that contribute to cumulative trauma disorders in the office,
namely, repetitive work without adequate recovery time; sustained static exertions-prolonged
holding of a single posture; forceful exertions, use of excessive strength during any activity;
localized contact stresses and pressures on the soft tissues caused by external surfaces
(e.g., constant rubbing against a desk edge). Chronic musculoskeletal disorders, associated
with repetitive work, are also of increasing concern to industry, employees, workers'
compensation insurance carriers, and regulatory agencies (Sjogaard, 1990:1).
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According to Carcone and Keir (2006:755) while comfort is an important criterion to the user,
there has been little research to relate comfort to biomechanical variables, such as pressure
or lower back posture in office seating. Incorrect lumbar spine posture during sitting has been
linked to lower back pain (Dolan, Adams and Hutton, 1988:197; Wilder and Pope, 1996:61).
However, posture measurements when seated typically require alterations of the backrest
and use of cumbersome equipment, both of which are likely to alter natural behavior and
sitting posture of the user (Bendix, Poulsen, Klausen and Jensen, 1996:533).
Research on upper limb disorders in adults has shown that functional impairment, pain and
discomfort in upper limbs, neck and shoulder increases with frequency and duration of
exposure to computer use (Bernard, 1997:1; Evans and Patterson, 2000:35). Lucas (2007:2)
describes how desk jobs cause neck and shoulder problems, which could eventually leading
to arm and wrist problems. Neck and upper limb symptoms are frequently reported by
computer workers (Bernaards, Ariëns and Hildebrandt, 2006:80). Punnett and Bergqvist
(1997:2) cautions management to take heed of the increasing financial impact of injuries
caused by extended computer usage. Without comfortable workstations employees are
forced to continue repetitive movements which eventually lead to upper limb pain and injury.
The available epidemiological evidence suggested that hand, arm, shoulder and neck
symptoms are associated with the duration of computer use and, in fact, increase steadily
with each hour of computer use per day (Punnett and Bergqvist, 1997:2). It should be noted
that previous studies by Homan and Armstrong (2003:48), Heinrich, Blatter and Bongers
(2004:1027), Douwes, Blatter and de Kraker (2004:113) and Lassen, Mikkelsen, Kryger and
Andersen (2005:122) relied on self reports for the measurement of the duration of computer
use. The same authors however explained that the use of self-reports may lead to
overestimation of the duration of computer use, which might result in misclassification.
A systematic review of available literature indicate that these associations are evident
internationally and across studies in spite of variations in study design, case definition and
terminology which pose barriers to direct comparisons between data sets (Harrington et al.
2000:264). Computer screen glare, posture and workspace suitability have all been
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associated with headaches and other symptoms (Alexander and Currie, 2004:256). Neck and
shoulder pain has been associated with time spent computing, postural deviations and
muscle loading (Bernard, 1997). According to Paoli and Merllié (2000:1) over 50 million
European workers reported using the computer at least half of their working hours. Recent
large-scale surveys showed one-year prevalences of hand, arm, shoulder and neck
symptoms ranging from 24 to 44% among office workers (Juul-Kristensen, Sogaard, Stroyer,
and Jensen, 2004:390; Jensen, 2003:197; Lassen, Mikkelsen, Kryger, Brandt, Overgaard,
Thomsen, Vilstrup and Anderson, 2004:521).
The need clearly exists for executives to explore ergonomic risk factors and to address the
key areas which continuously result in a poor working posture.
2.3. LOWER-BACK PAIN
Over the past century, there has been an increase in the proportion of seated occupations
(van Dieen, de Looze and Hermans, 2001:739). These jobs, although generally less
physically demanding, are a risk factor for the development of lower back pain (Cartas et al.
1993:603; Lengsfeld et al. 2000:665; Videman et al. 1990:728). Individuals tend to adopt
passive or slumped postures when seated for a prolonged duration (Andersson, Ortengren,
Nachemson, Elfstrom and Broma, 1975:105; Adams, Hutton and Stott, 1980:245; Adams and
Hutton, 1985:625; Hedman and Fernie, 1997:734). The same authors concluded that
prolonged sitting may lead to lower back pain due to deactivation of the erector spinae
muscles, thus relying on spinal ligament support, which may lead to injury over time.
Johanning (2000:94) confirms that lower back pain and disability are among the leading
causes of occupational injury in industrialized countries. Pope et al. (2002:50) concur that
occupational lower back pain is an immense burden for both industry and health care
systems. Moreover, lower back pain represents the most common cause of disability in
persons under 45 years of age which encompasses a major component of the work force
(Bigos et al.1994:0642).
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According to Van Vuuren et al. (1991:2) lower back problems constitute one of the most
challenging medical problems in industrial countries. The same authors confirmed a high
prevalence and cost implication linked to chronic work-related spinal disorders. It is further
commonly accepted that 50–80% of the population suffers from idiopathic lower back pain at
least once in their lifetime (Zinzen, 2002:41). The role of pain-related fear and its associated
avoidance behaviour in the development of chronic musculoskeletal pain has received
increased attention (Asmundson, Norton and Norton, 1999:97; Al Obaidi, Nelson, Al Awadhi
and Al Shuwaie, 2000:1126; Vlaeyen and Linton, 2000:317 and Swinkels-Meewisse, Roelofs,
Verbeek, Oostendorp and Vlaeyen, 2003:371). Although heavy manual labour as an
occupational trend has decreased, the prevalence of lower back pain has increased.
According to Deyo (1998:49) work disability related to back pain has risen steadily, despite
economics being increasingly post-industrial with a reduction in manual labour.
Seventy percent of spinal disorders, involving the lumbar spine, are treated by
physiotherapists (Spitzer 1987:51). Occupational exposure to fixed postures and prolonged
sitting has become a risk factor to both employee and employer. Pope et al., (2002:56)
confirms that there is an increase in symptoms in those with lower back pain who sit for
prolonged periods. According to Graf et al. (1998:81) back disorders and discomfort are major
sources of lost work time and worker dissatisfaction.
Workers who undergo periods of static or cyclic trunk flexion have an increased risk of lower
back pain (Marras, Lavender and Leurgans, 1993:617; Punnet, Fine, Keyserling, Herrin and
Chaffin, 1991:337). Biomechanical factors contributing to this risk may include excessive or
cumulative spinal loading (Kerr, Frank, Harry, Norman, Wells,, Neumann and Claire,
2001:1069), ligament and disc strain (Dolan, Earley and Adams 1994:1237), and spinal
instability (Omino and Hayashi, 1992:693). Active muscular recruitment and reflexes play a
major role in both spinal and ligamentous load as well as spinal stability (Gardner-Morse and
Stokes, 1998:86; Granata and Marras, 1995:1309).According to Snijders, Hermans, Niesing,
Jan Kleinrensink and Pool-Goudzwaard (2007:2) lower back pain is often attributed to
intolerable high intradiscal pressure as a result of long-term sitting.
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Poor posture can be a cause of back pain and therefore it should be corrected to prevent
constant discomfort (Neumark, 1998:D8). Ose (2005:161) substantiates this claim by stating
that poor posture can often be the result of high degrees of monotonous work and/or frequent
heavy lifting. A growing number of studies have suggested that people with lower back pain
may have deficits in postural coordination, such as deficits in the coordination of whole-body
voluntary movements (Cacciatore et al. 2005:565).
In particular, anticipatory postural adjustments, which precede voluntary movements to
stabilize the body in advance, are abnormally coordinated in people with lower back pain
(Hodges and Richardson1996, 1998 & 1999). People suffering from lower back pain also
have deficits in standing and seated balance compared too people without lower back pain
and may have deficits in automatic postural coordination (Byl and Sinnott, 1991:328; Meintjies
and Frank, 1999:710; Alexander and La Pier, 1998:378; Radebold, Cholewicki, Polzhofer and
Greene, 2001:724).
Economic analysis of work-related lower back disorders has focused on work absence among
the employed and found it to be common as well as expensive to alleviate (Wynne-Jones et
al. 2007:1). According to the same authors the cost of lower back pain to employers is high,
with an estimated £9090 million lost in the United Kingdom in1998. Lower back pain affects
58 to 84% of all adults at some point in their life place a significant burden on health services
internationally (Goubert et al. 2004:390).
A major point of concern according to van Vuuren, van Heerden, Becker, Zinzen and
Meeusen (2007:2) is that although literature on the epidemiology of lower back pain is
accumulating, for the most part studies are restricted to high-income countries, which
comprise less than 15% of the world's population. Volinn (1997:1747) agrees that very little is
known about the epidemiology of lower back pain in the rest of the world.
Considered from medical, social or economic perspectives, the cost of musculoskeletal
injuries experienced in the workplace is substantial, and there is a need to identify the most
efficacious interventions for their effective prevention, management and rehabilitation
(Boocock, McNair, Larmer, Armstrong, Collier, Simmonds and Garrett 2006:291).
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2.4. POSTURE
According to Loots (2004:2) good posture represents the state of balance in an individual at
rest and during motion. Ideal posture involves a minimal amount of stress which is conducive
to maximal efficiency in the use of the body (Montgomery and Connolly, 2003:186). According
to Montgomery and Connolly (2003:186) ideal posture is one that requires minimal muscular
activity to maintain and allows for maximum movement efficiency. Posture is also a reflection
of the “position” of many systems that are regulated, determined and created through limited
functional patterns (Hruska, 2002:1).
There have been many previous attempts in literature to evaluate computer users’ posture,
however, only a few have focused on evaluating a physical programme used as an
intervention to improve postural control (Emmons and Wilkinson, 2001:77-87; Pope et al.
2002:49-68; Jonai et al. 2001:219-229; Lucas, 2007:1-7). As mentioned before the
slumpedposture is typical of a computer user. The upper cross posture syndrome, affecting
the head, neck and shoulders, is the source of computer user’s complaint of chronic neck and
shoulder tightness and pain (Cipriano, 2003:26)
The centre of gravity is a fundamental orientation that must be defined to facilitate analyzing
movements (Hyde, 2002:46). Hyde (2002:46) describes the centre of gravity as the point
where the body balances on both sides as well as in all planes without the tendency to rotate,
fluctuate or fold. To maintain upright stance, the central and peripheral components of the
nervous system are constantly interacting to control body alignment and the centre of gravity
over the base of support (Alexander and La Pier, 1998:378).
To maintain erect posture and balance, the lumbar erector spinae muscles compensate and
extend the spine, resulting in hypertonicity of the lumbar erector spinae and adapting
weakening of the opposing abdominal muscles (Cipriano, 2003:27). According to Thompson
and Hunt (1984:1) static stability is achieved when the posture of the spine is in equilibrium
and also in a state of minimum energy expenditure. Herrington and Davies (2003:52) confirm
that the neuromuscular system acts to maintain postural stability and reduce the impact of
deleterious loads on the spine.
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Muscle recruitment, spinal posture, and external load contribute to the energy expenditure of
the musculoskeletal system (Bergmark, 1989:1; Gardner-Morse, Stokes and Laible,
1995:802; Granata and Wilson, 2001:650).
Skelton (2001:34) defined balance as a complex automatic integration of several body
systems. According to Cote, Brunet, Gansneder and Shultz (2005:42) peripheral components
in balance include the somatosensory, visual, and vestibular systems. The postural control
system’s aim is to coordinate and maintain the stability of the multiple degrees of freedom of
the body (Chiari and Cappello, 2005:271). According to the same authors this system
includes several interacting components, namely the skeletal, muscular, neural and sensory
systems. Van Daele, Huyvaert, Hagman, Duquet, van Gheluwe and Vaes (2007:44) confirm
that integrated information from these three independent sensory sources is used to maintain
postural stability. The reciprocal integration of these sensory systems will be discussed in the
next section on postural stability.
2.5. POSTURAL STABILITY
The task of postural control involves controlling the body’s position in space for stability
(defined as controlling the centre of body mass relative to the base of support) and orientation
(defined as the ability to maintain an appropriate relationship between body segments) and
between the body and the environment for a task (Shumway-Cook and Woollacott,
2006:184).
Occupational postures such as sitting at a desk and standing during lunch breaks have an
effect on postural stability. Andersson and Ortengren cited in Kayis and Hoang (1999:255)
stated that during sitting, the activity of the back muscles is similar to that during standing, but
in supported sitting, as with the elbows resting on the knees, there is no activity in the lumbar
back muscles. With arms resting on a desk, back muscle activity is substantially decreased
(Andersson and Ortengren cited in Kayis and Hoang (1999:255). In the seated individual, the
“slumped” posture, or fatigued position, is characterized by a flattened lumbar spine (loss of
normal lordosis), an increased kyphosis of the thoracic spine, protracted scapulae, and
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usually by a flattened cervical spine with the head forward (Travell and Simons, 1983:548).
Furthermore Travell and Simons (1983:548) emphasize that this type of posture leads to
multiple muscle and joint problems in the trunk, upper limbs, neck, and head, as well as
limited respiratory function.
With high work demands placed on workers, the inclination is to pay less attention to postural
stability. Since normal postural stability occurs automatically, without conscious effort, it was
assumed that further muscular recruitment was needed to control balance (Shumway-Cook
and Woollacott, 2006:184). The same authors however proved that there are significant
requirements for postural stability, and that these requirements vary depending on the
postural task, on the age of the individual, and on the individual’s balance abilities. Some of
these requirements include body alignment (which minimizes the effect of gravitational
forces), muscle tone, and postural tone (which keeps the body from collapsing in response to
the pull of gravity (Shumway-Cook and Woollacott, 2006:185).
Branton, cited in Hendriks, Spoor, de Jong and Goossens (2006:1611) hypothesized that
there is continual need for postural stability while sitting. According to Carcone and Keir
(2006:755) while comfort is an important criterion to the user, there has been little research to
relate comfort to biomechanical variables, such as pressure or lower back posture in office
seating. The maintenance of postural stability in the seated position has not been studied in
depth (Shumway-Cook and Woollacott, 2006:186). The same authors confirm that concepts
important for standing postural stability will be shown to be equally valid for postural stability
during sitting.
Poor seated posture is often exaggerated by poorly designed workstations that offer little
movement for the employee to adjust or adapt him or herself. Also, poor body posture and
inadequate seat support have been described as co-factors in the pathogenesis of
musculoskeletal disorders of the spine (Burdorf, Derksen, Naaktgeboren, van Riel, 1992:263).
Ostrom (1981), cited in Waikar and Bradshaw (1995:18), pointed out that “dynamic sitting”,
implying a change in posture every five minutes, is important for comfort and promoting good
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circulation. Travell and Simons (1983:548) confirms that frequent changes of position are
needed to promote health of the muscles and intervertebral discs.
According to Loots (2004:1) postural training in general could therefore be beneficial for both
body and mind, and an appreciation of good posture and its resulting efficiency represents the
best kind of preventative medicine. The results of Adkin, Carpenter and Frank (2003:2)
provide converging evidence in identifying balance as a key modulator of postural control.
With this in mind, Salavati, Moghadam, Ebrahimi and Arab (2006:1) affirm that the
maintenance of balance is an essential requirement for the performance of daily tasks and
sporting activities. In order to maintain postural control, humans continuously use information
form somatosensory, visual and vestibuar sources, resulting in efferent signals that activate
appropriate postural muscles (Gustafson, Noaksson, Kronhed, Moller and Moller 2000:168-
172). It is well known that the central nervous system (CNS) preserves stability of the body by
generating postural adjustments simultaneously with or just prior to the initiation of voluntary
movement (Massion 1992:35). Shumway-Cook and Woollacott (2006:185) confirm that each
sense (visual, somatosensory and vestibular systems) provides the CNS with a different kind
of information about position and motion of the body thus; each sense provides a different
frame of reference for postural stability.
Toussaint, Michies, Faber, Commissaris & van Dieen (1998:85) conclude that the magnitude
and timing of these postural adjustments is critical and depends on the physical demands
associated with the movement as well as the behavioural context in which the movement is
performed. According to Horak & Macpherson (1996:255) postural adjustments, based on the
integration of a rich source of sensory information, are matched to the parameters associated
with the task and are modified by the context in which the task is performed.
Salavati et al. (2006:1) states that several studies have examined how pathologic conditions,
aging and fatigue affect postural stability. The same author emphasizes that muscular fatigue
impairs proprioception and postural stability. Neck, mid-back and especially lower back pain
often result from an unbalanced posture. As a result of these unbalanced activities, the most
used muscles of the chest (the pectoralis group) and the inward rotation of the shoulders tend
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to be comparatively over-strong and shortened (Frost, 2002:140). The same author states
that their opponents, external rotators consisting of the supraspinatus, infraspinatus, teres
minor and subscapularis, tend to be weak and lengthened. According to Rybski (2004:731)
the round back, or increased kyphosis in the thoracic spine, results in tight anterior-
intercostals (pectoralis major and minor, latissimus dorsi and serratus anterior), stretched and
weakened scapulae retractors, and stretched thoracic erector spinae. In order to correct the
postural imbalances, specific exercises are needed to strengthen, and thereby shorten the
neglected muscles and also to stretch the incorrectly shortened ones (Frost, 2002:141).
Since gravity is a constant force our bodies are designed to respond to it. Balasubramaniam
and Wing (2002:531) conclude that forces arising from gravity, external events or our own
actions, all tend to disturb the unstable equilibrium that preserves posture. The authors
furthermore continue to state that loss of balance automatically activates a neuromuscular
reaction Balasubramaniam and Wing (2002:532) affirms that posture should be actively
maintained so that joints between body segments are free to move under external forces that
could be constant or variable in nature.
Following appropriate postural education (both static and dynamic), the patient/employee can
take responsibility for the management of pain that results from chronic postural strain and
many activities of daily living (Travell and Simons, 1983:548). The same author makes the
profound statement of the more aware we become of poor posture the more likely we will
exercise control over it.
2.6. PHYSICAL EXERCISE AS AN INTERVENTION FOR BOTH MIND AND BODY
Accumulating evidence indicates that physical activity and structured exercise help maintain
an independent life by maintaining postural stability, strength, endurance, bone density and
functional ability (Skelton, 2001:33). The benefits of physical activity to the mind and the body
have long been acknowledged by health professionals (James and Johnston, 2004:77).
According to Long and Flood (1993:109-19) physical activity stimulates muscle relaxation
after physical exertion and can distract workers from stressful work aspects. Furthermore, the
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same authors state that physical activity may reduce stress through increased self-efficacy
and self-esteem. According to Bernaards et al. (2006:81) increasing physical activity might be
effective in reducing neck and upper limb symptoms. Physical exercise programmes have
been adopted in the workplace and used successfully in many oriental countries such as
China, Japan and Korea (Waikar and Bradshaw, 1995:16).
Several other studies have been published on the effectiveness of exercise programmes to
reduce pain and disability in patients with neck and shoulder symptoms (Levoska and
Keinanen-Kiukaanniemi, 1993; Takala et al. 1994:19; Klemetti, Santavirta, Sarvimaki and
Bjorvell, 1997; Gowans, DeHueck, Voss and Richardson, 1999; Taimela, Takala, Asklöf,
Seppälä and Parviainen, 2000; Horneij, Hemborg, Jensen and Ekdahl, 2001; Waling,
Jarvholm and Sundelin, 2002; Kjellman and Oberg, 2002; Viljanen, Malmivaara, Uitti, Rinne,
Palmroos and Laippala, 2002; Tsauo et al. 2004:253; Ylinen et al., 2003:2510; Sjögren,
Nissinen, Jarvenpaa, Ojanen, Vanharanta and Malkia, 2005; Chiu, Lam and Hedley, 2005).
However, most of these studies show only short-term effects of exercise programmes
(Levoska and Keinanen-Kiukaanniemi, 1993; Taimela et al. 2000; Kjellman and Oberg, 2002;
Tsauo et al. 2004:254; Sjögren et al. 2005). Lifestyle physical activity interventions that aim to
increase physical activity up to at least thirty minutes per day seem to be promising with
regard to the maintenance of physical activity (Prochaska, DiClemente and Norcross,
1992:1102).
With specific reference to decreasing lower back pain Kavcic, Grenier and McGill (2004:1254)
confirm that postural stability exercises assist the skeletal muscles around the vertebral
column to act as load absorbers, thereby stabilizing the spine. Increased strength of trunk
flexors and extensors muscles are thought to raise intra-abdominal pressure and to decrease
spinal loading (Aspden, 1988:268; Morris, Lucas and Bresler, 1961:3288). This in turn
according to Lee, Hoshino, Nakamura, Kariya, Saita and Ito (1999:54) may reduce the
occurrence of back problems.
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2.7. THE PILATES METHOD AS INTERVENTION STRATEGY TO TRAIN POSTURAL STABILITY
Pilates is a mode of exercise developed by the late Joseph Pilates (Hastings 2001:12).
According to Owsley (2005:19) Joseph Pilates was born in Dusseldorf, Germany, in 1880. As
a child he suffered from asthma, rickets and rheumatic fever (Shedden and Kravitz,
2006:111). Joseph Pilates was a German expatriate who first made his mark in England
during World War I when he developed a series of exercises and innovative equipment to
help prisoners of war regain strength and mobility. Following World War I Spanish influenza
broke out, not a single prisoner or guard from the prison camp died during the pandemic
(Owsley ,2005:19). It was at this time that Joseph Pilates began devising the system of
original exercises today known as “mat-work”, or exercises done on the floor.
Joseph Pilates had designed ways for wounded soldiers to rehabilitate muscles in their
hospital beds during World War I (Chessher, 1998:44). Jospeh Pilates moved to New York
set up an exercise studio where he taught professional ballet dancers and refined his
teaching method (Giusti, 2003:28).
It is estimated that currently in the USA 25 million people regularly participate in Pilates
classes and more than one million do the same in the UK (Is Pilates bad for your Back?
2007:1). The objectives of Pilates exercises programme are to increase muscle strength,
endurance, and flexibility together with the maintenance of spinal stability (Shedden and
Kravitz, 2006:111). According to Pilates Perfection (2002:1) Pilates exercises simultaneously
address the components of flexibility, strength, while emphasizing body symmetry and
abdominal control during movement.
According to Solie (2007:19) Pilates is a method of mind-body conditioning, where core
exercises are designed to create an awareness of the deep thoracic and abdomino-pelvic
muscles and to readjust any musculoskeletal imbalances. Pilates exercises are focused on
the stabilizing contractions of the postural muscles (Muscolino and Cipriani, 2004:122). All
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movements are performed and coordinated with breathing patterns and accurate body
alignment to provide maximum results with minimal repetition. Cassity (2004:86) reiterates
that the use of Pilates as a method of training could enhance biomechanical functioning of the
body, balance, co-ordination, postural and spatial awareness, strength and flexibility. These
improvements in the physical body also have a positive effect on the mental health of the
participant (Russell, 2006:1).
Pilates exercises are performed in a neutral spine position. According to Owsley (2005:22) a
neutral spine is defined as the point halfway between a posterior pelvic tilt and an anterior
pelvic tilt. A neutral spine is biomechanically and functionally correct to maintain good posture
(Liemohm and Pariser cited in Owsley, 2005:22).
According to Baker (1999:2) studies have illustrated the specificity of roles of the abdominals
between trunk flexion and lumbo-pelvic stabilization. The multifidus and transverse
abdominus stabilize the spine through co-contraction (Panjabi, 1992:390-397). Postural
muscles, including the anterior and posterior abdominal wall musculature, provide trunk
stability, which is crucial to balance and postural stability (Mullhearn and George cited in
Johnson, Larsen, Ozawa, Wilson, Kennedy, 2006:1). The abductor and adductor muscles of
the hip joint, situated in the femoral triangle, provide optimum stability and mobility to the hip
and lumbo-pelvic area when in a balance position (Drake, Vogl, and Mitchell, 2005:502).
Richardson and Jull, cited in Baker (1999:2), confirms that as far as the pelvic stability is
concerned, strong abdominal muscles, especially the deep transverse abdominus and the
internal and external obliques, allow for the proper positioning of the pelvis and hence, the
limbs and spine during tasks such as running and jumping. Crews (2006:59) emphasizes that
the contraction of the pelvic floor muscles, along with other synergistic musculature
(piriformis, obturator internus, rectus abdominus, internal and external obliques and
transverse abdominus), contribute to spinal and pelvic stability. Gardner-Morse and Stokes
cited in Shedden and Kravitz (2006:111), support this latter finding of reciprocal interaction
between relevant musculature.
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According to Loots (2004:1) postural rehabilitation has physical and psychological
considerations. This was demonstrated by improvement in posture and increased body
awareness, a decrease in the tendency to become fatigued, a decrease in back and neck
stiffness and improvement in mental attitudes. Owsley (2005:19) confirms that little evidence
exists in the literature with regard to computer users using a Pilates training programme as a
method of intervention to enhance postural stability. Kaesler et al. (2007:37) confirm that
Pilates as a movement system is purported to improve postural awareness through the
facilitation of movement re-education. It is the purpose of the current study to explore and
determine the effect of a Pilates intervention on postural stability in computer users.
Foltz-Gray (2003:77) states that an improper posture effects symmetrical movement and is
responsible for the inability to move freely. The author continues to argue that postural
education including postural awareness should impact upon the accuracy and symmetry of
movement performances, such as walking correctly. Bernardo (2007:106) supports literature
findings on the effectiveness of the Pilates method in improving flexibility and abdominal- and
lumbo-pelvic stability.
Mortensen, Kaiser, Gibb & Allsen (2004:39) explored the effects of a Pilates-based
conditioning programme on two-footed vertical jump and single-leg hop in modern dancers.
The experimental group (n=13) participated in the daily technique class, as well as a 50-
minute Pilates-based conditioning programme three days a week. Results showed that there
may be an advantage to using the Pilates-based conditioning programme to improve single-
leg hop height in modern dancers. Other relevant studies include Segal, Hein and Basford
(2004:1977 – 1981) who used an observational study to evaluate the effect of Pilates on
flexibility and body composition and concluded that overall flexibility did improve. Johnson et
al., (2006:4) found that Pilates-based exercise improved dynamic standing balance in healthy
adults.
Johnson et al., (2006) used Pilates as an intervention method and found that ten Pilates-
based exercise sessions, using healthy adults, resulted in a significant change in dynamic
balance. Gladwell, Head, Haggar and Beneke (2006:338) evaluated the effect of a
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programme of modified Pilates for active individuals with chronic non-specific lower back pain.
The experimental group participated in a six week Pilates intervention programme indicating
an overall improvement in functional movement.
According to Rydeard (2002:1) a randomized controlled trial, with a pre-test, post-test design
(Part I, main study) with a 3, 6 and 12-month postal questionnaire follow-up (Part II) was
used. The treatment group participated in a 4-week programme offered by a physiotherapist
while the non-treatment group received usual care and no specific treatment intervention. A
treatment programme was designed to train trunk stability and neuromuscular performance
during movements involving hip extension utilizing Pilates apparatus and a home programme.
In the main study the treatment group demonstrated a significant reduction in average pain
intensity compared to the non-treatment group.
The principles outlined by Joseph Pilates in his book Return to Live through Contrology are
still relevant today (Pilates cited in Owsley 2005:21) and as such provided guidelines for the
Pilates intervention programme design and prescription followed by the participants in this
study. According to Owsley (2005:21-22) the eight principles which underpin the performance
of each of the exercises are; concentration, co-ordination and control, centering and
alignment, flow of movement, precision, breathing, relaxation, and stamina.
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2.8. SUMMARY
In a technological working world the use of computers is inevitable in everyday life. Static
working positions will continue to disrupt the working relationship between employee and
employer if an effective programme is not implemented. Absenteeism due to neck pain and
low back pain, amongst other complaints, will continue to affect productivity. Physical exercise
programmes should be used as a method of controlling and maintaining posture and postural
stability. Creating awareness and postural educational programmes should become a primary
goal and concern to both an employee and employer. Pilates, developed by the late Joseph
Pilates, should be used to contest and control imbalanced postures, incorrect pelvic alignment
and asymmetrical body movements.
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CHAPTER 3: METHODS AND PROCEDURES
3.1. Introduction
3.2. Research Design
3.3. Research Participants
3.4. Data Collection Methods
3.5. Measuring Instrument
3.6. The Pilates Intervention Programme
3.7. Data Analysis
3.8. Ethical Considerations
3.9. Summary
3.1 INTRODUCTION
The preceding chapters have served to support the reasoning behind the present research
study. In chapter 2 an overview of available literature on ergonomics, lower back pain,
posture, postural stability and the use of Pilates to achieve good posture and postural stability
were given. This was done to provide a foundation for the study.
The present chapter provides an overview and description of the research design and
methodology employed in this study. A detailed description of the measuring instrument, the
Biodex Stability System, will also be provided. This chapter also gives a clear depiction of
how this study was carried out, the way in which participants were chosen and the manner in
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which data was collected and analyzed. The ethical considerations taken into account will
also be discussed.
3.2. RESEARCH DESIGN
This study employed an exploratory, descriptive quasi-experimental, non-equivalent group
approach. This design was used to gather quantitative data, collected through pre- and post
tests, for statistical analysis.
Typically, a research process begins with an exploratory study for preliminary identification of
possible factors or variables, then moves to a descriptive study to define the salient or key
variables, and concludes with a causal study, such as an experiment, to test the variables for
strength of association or cause-and-effect relationships (McNabb, 2004:134). The same
author explains that exploratory research is conducted for the reason of gathering insight into
an issue. Rubin and Rabbie (2001:123) conclude that the exploratory design is typically used
when a researcher is examining a new area of interest, or the subject of the study is relatively
new and unstudied, or a researcher seeks to test the feasibility of undertaking a more careful
study.
According to De Vos (2000:214) the exploratory design explores the nature of the problem,
the extent to which the problem is known to the researcher, and the quantity and quality of the
information available on the relevant subject will determine the manner, range and depth of
the relevant exploratory study. Exploratory research is conducted when a research problem or
issue has very few or no earlier relevant studies to which to refer to for information about the
issue or the problem (Collis and Hussey, 2003:10). The same authors conclude that this
approach to research is usually very open and concentrates on gathering a wide range of
data and interpretations.
A quasi-experiment is a design which is similar to a true experiment, but differs in that one or
more characteristics of a true experiment are missing (Kerr, Griffiths and Cox, 1996:67). A
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design is quasi-experimental if subjects are not randomly assigned to groups but there is still
a control or comparison group (Garson, 2007:1). This category of design is most frequently
used when it is not feasible for the researcher to use random assignment. A quasi-
experimental design is a study which has most of the trappings of an experiment, but which is
unable to control potential factors, or perhaps is not guided by an idea of what all the factors
are (Kilty, 2002:1). The same author warns that this lack of control sometimes leaves quasi-
experiments with dubious outcomes, such as a lack of consistent internal logic and other
invalid reasoning.
In situations where it is known that only a small sample size will be available to test the
efficacy of an intervention, randomization may not be a viable option (Harris, McGregor,
Furuno, Zhu, Peterson and Finkelstein, 2006:16-23). According to Harris et al. (2006:16-23)
quasi-experiments are studies that aim to evaluate interventions, but that do not use
randomization. Trochim (2006:1) agrees that a quasi-experimental design appears to be like
an experimental design, but lacks the key ingredient of random assignment. The same author
concludes that there is something compelling about these designs that are easily more
frequently implemented in field research than their randomized alternatives.
According to Trochim (2006:1) the non-equivalent group design is probably the most
frequently used design. It is structured like a pretest-posttest randomized experiment, but it
lacks the key feature of random assignment. In quasi-experimental designs, targets receiving
the intervention are compared to a control group of selected, non-randomly assigned targets
that do not receive the intervention (Rossi, Lipsey and Freeman, 2004:247).
The quasi-experimental designs have been developed to control as many threats as possible.
Since participants are not randomly assigned to groups, one cannot assume that the
populations being compared are equivalent in all aspects prior to the treatment, and
accordingly internal validity is threatened. Shadish, Cook and Campbell (2002:1) cited in
Harris et al. (2006:16-23) outline nine threats to internal validity, namely ambiguous temporal
precedence, selection, history, maturation, regression, attrition, testing, instrumentation and
interactive effects.
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The lack of random assignment of participants is the major weakness of the quasi-
experimental study design. Researchers often choose not to randomize the intervention for
one or more reasons; namely, ethical considerations, difficulty of randomizing subjects,
difficulty to randomize by locations, and small available sample size (Harris et al. 2006:16-23).
The use of both a pretest and a comparison group makes it easier to avoid certain threats to
validity; however selection may still be biased. According to De Vos et al. (2002:145) the
comparison group pretest-posttest design utilized, is the equivalent of the classical
experiment, but without random assignment of subjects to the groups. The experimental and
comparison groups will undergo a pretest to indicate the extent of their differences (De Vos et
al. 2002:146).
Quasi-experiments aim to demonstrate causality between an intervention and an outcome.
These designs were developed to provide alternate means for examining causality in
situations which were not conducive to experimental control. Similar to randomized trials,
quasi-experiments aim to demonstrate causality between an intervention and an outcome
(Harris et al. 2006:16-23).
3.3. RESEACH PARTICIPANTS
The sample of this study included male and female computer users from the Nelson Mandela
Metropole undergoing Pilates as an intervention programme to improve postural stability.
Forty healthy male and female participants volunteered to participate. The age range of the
participants was 25 – 59- years-old. An inclusion criterion was that the participants must have
been using a computer for at least three years. The reason for choosing a wide sample age
range, is that Pilates can be performed and benefit individuals at any age. It offers a solution
to those with restricted mobility, elite athletes, and has been as beneficial for an 11-year-old
as it is for an 80-year-old (Isacowitz, 2006: xvi). Furthermore, as the sample population was
dependent on convenient or accidental sampling, only volunteers who committed themselves
to the study were selected. De Vos et al., (2002:207) defines accidental sampling as including
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any case that happens to cross the researcher’s path and is relevant to the phenomenon in
the sample until the desired number has been obtained.
A sample of twenty participants in both the experimental and control group meant that a total
of 40 participants took part in the research study. However three participants in the
experimental and the control group respectively did not complete the study, due to time
constraints. This meant that the study experienced a 15% drop-out rate. According to the
researchers Reid and Smith (1981) and Sarantakos (2000) in De Vos et al. (2002:199), a
complete coverage of the total population is seldom possible, and all the members of a
population of interest cannot possibly be reached. However, a large sample needs to be
drawn as a certain degree of participant mortality and drop-out occurs in any research (De
Vos et al. 2002:200). Hence, in concurrence, a study sample was chosen which included
individuals aged between19 and 55 years of age. This was done to ensure a wide range of
the population through varying age groups with the intention of determining whether similar
effects on the postural sway and lateral sway variables could be perceived throughout the
range of participant age groups.
3.3.1. SAMPLING DESIGN AND TECHNIQUE
The participants, computer users, in this particular study were selected using non-probability
convenience sampling. According to Gerrish and Lacey (2006:175)
non-probability samples consist of people from whom the researcher finds it convenient to
collect data (Whitley 2002:394; Polit and Beck, 2004:292 ), and, by definition, easy to access
(Lewis-Beck, Bryman and Liao, 2004:197). Non-probability methods have the advantages of
being cost-effective, can be used when the sampling frame is not available, are useful when
the population is so widely dispersed that cluster sampling would not be efficient, and are
often used in exploratory studies (Gilles, 2002:77). However, a non-probability sample, being
unrepresentative of a whole population, may demonstrate bias (Cohen, Manion and Morrison,
2000:99). Gilles (2002:78) agree that the likelihood of bias is high.
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Although convenience sampling has the aforementioned weakness, it remains the most
common form of sampling in the Social Sciences (Polit and Beck, 2004:292).
Volunteers were also obtained by means of snowball sampling in which participants already
involved in the study found other participants relevant to the study. De Vos et al. (2002:336)
defines snowball sampling as the collection of data on the few members of the target
population that can be located, and then seeks information from these individuals that
enables the location of other members of that population. Volunteers were obtained by the
placement of an advertisement on the NMMU staff and student e-mail portals. After approval
by the Biokinetics and Sports Science Unit (BSSU) of The Nelson Mandela Metropolitan
University (NMMU), the participants were contacted either by telephone, email or direct
consultation to organize the most suitable times for testing on the Biodex Stability System.
Written consent forms (Appendix A) were obtained from each participant prior to the
commencement of the assessment.
3.3.2. EXCLUSION CRITERIA
Female participants beyond the first trimester of pregnancy were not included as part of the
control or experimental group as performance of the Pilates exercises required participants to
be positioned in a supine position and uterine blood supply could have been negatively
affected. Individuals younger than 18 years of age, were furthermore excluded from
participation, since they require parental or guardian permission before participating in an
exercise programme. Furthermore the differentiation between male and female participants
was not made as the study numbers were too small.
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3.4. DATA COLLECTION METHODS
Formal consent was obtained from the Biokinetics and Sports Science Unit (BSSU) of The
Nelson Mandela Metropolitan University (NMMU) in order to conduct the assessment, using
the Biodex Stability System. The identified participants were then contacted by the researcher
to explain the nature of the research study and to gain verbal consent for their participation.
Once the various individuals verbally agreed to participate in the study, they were either given
an envelope by hand or electronically which explained in detail all necessary information
regarding their participation.
Each participant received a letter of informed consent concerning the nature, purpose and
procedure of the study (Appendix B and C). The BSSU assisted with the administration of the
assessment at both the pre- and post test phases. The Biokinetics interns were briefed and
trained on the purpose and use of the Biodex Stability System as a measuring instrument to
assess postural stability, as well as given instructions for the exact procedure to follow in
completion of the assessment if the researcher could not be present.
The methods and procedures of testing that guided the assessments, were those used in
compliance with The Biodex Stability System Manual (2000). When performing a postural
stability test it is important to remember that a participants’ score on the test assesses the
deviations from the center, therefore a lower score would be more desirable. The following
testing protocol was used to assess the participants: three test repetitions, at the same time,
using a two legged stance at stability level of eight, for the duration of twenty seconds each
(The Biodex Stability System Manual 2000:8-6). In order to negate the learning effect the first
trial has not been used in the statistical analysis. Each participant completed the testing in
less than twenty minutes and the corresponding results were instantaneously printed by the
Biodex Stability System.
The postural stability test results were then analyzed by a qualified statistician at the Nelson
Mandela Metropolitan University. A verbal report, pertaining to the participants’ scores, was
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provided by the researched on request of individual participants, who asked for feedback of
their results.
3.5. MEASURING INSTRUMENT
The Biodex Stability System (950-304) was used to measure the postural stability of the
participants. The Biodex challenges a participants’ balance while standing on a movable
platform that tilts to a maximum of twenty degrees in different directions. The system uses a
mechanical system which ranges from level one to level twelve, where level one represents
the greatest instability. According to the Biodex Stability System Manual (2000:8-6) the test
protocol commonly used with the Biodex Stability System is a Dynamic Balance test. The
following protocols were used in this study to maintain reliability and validity; namely, a test
duration of twenty seconds at a stability level of eight using a two legged stance (Appendix
D).
According to The Biodex Stability System Manual (2000:1-2) using this unique device,
clinicians can assess neuromuscular control by quantifying the ability to maintain dynamic
bilateral and unilateral postural stability on a static or unstable surface. Most of the balance
tests performed on the Biodex has been used in clinical settings due to the fact that
facilitators require minimal specialized training and instrumentation. To understand more
clearly the mechanics and functioning of the Biodex see (Appendix E).
According to Hinman (2000:242) when used in the testing mode, the Biodex system provides
an overall stability index (OSI) that represents the variance of the foot platform displacement
in degrees, from a level position, in all the ranges of motion during the test. Greater amounts
of body movement associated with an unstable posture produce high OI’s; a low OI indicates
little body movements and is associated with a more stable posture. Stability indexes (SI’s)
are also calculated for the anterior-posterior (AP) and medial-lateral (ML) directions, which
represent the variance of platform displacement for motions occurring in the sagittal and
frontal planes, respectively. In addition, the Biodex system displays the platform as a series of
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concentric circles, or zones, that are divided into 4 quadrants. The percentage that an
individual spends in each zone and quadrant is reported along with the SI values.
Reliability and validity are both important factors to take into consideration when conducting
research (De Vos et al. 2002:120). Factors that were taken into consideration to ensure
reliability and validity in this study include the standardized protocols utilized when using the
Biodex Stability System. The Biodex Stability System was used specifically, in testing format,
to measure the dependent variable of postural stability.
Reliability of a measure is its degree of consistency. A perfectly reliable measure gives the
same result every time and is applied to the same person or thing, barring changes in the
variable being measured (Whitley 2002:124). Validity measures the degree of accuracy.
The Biodex Stability System was shown to be reliable in several studies. Hinman (2000:249)
claims that the balance measures (SI) produced by the Biodex Stability System appear to be
reliable measures of postural stability. Research reported intra-class correlation coefficient
(ICC) values of 0.6 (for a stability level of eight) to 0.95 (for a stability level of two) in healthy
subjects (Pincivero, Lephart and Henry cited in Salavati et al. 2006:2).
A normative data was developed for bilateral stance with the pre-selected highest stability
level of eight. The Biodex Medical Systems is accredited with ISO 9001:2000 and ISO
13485:2003 certified companies.
3.6. THE PILATES INTERVENTION PROGRAMME
A clearly defined Pilates beginner mat based programme was designed based on the eight
Pilates principles as discussed in chapter two. Appendix (F) presents the selected exercises
performed with control using only eight to twelve repetitions per exercise. The duration of the
intervention programme lasted for an eight week period with a frequency of twice weekly at
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times suitable to the participants. The Pilates exercise sessions lasted sixty minutes and
included a warm-up and cool down phase.
The programme combines flexibility and strengthening exercises that emphasizes body
symmetry and abdominal control. Core exercises are designed to create an awareness of the
deep torso muscles and to re-pattern any muscular-skeletal imbalances. Attention was
particularly focused on accessing and training the core postural muscles that stabilize the
body and are essential to providing support for the spine in daily functional activities. All
movements are coordinated with breathing patterns and body alignment and precision and
accuracy in the quality of the movement performance was essential to provide maximum
results.
The mat based Pilates exercise sessions were performed in groups of four participants at a
time, to ensure proper supervision and correct performance of the exercises. An
internationally qualified and accredited instructor was utilized throughout the duration of the
study. Pilates mat based exercises are performed with control using only eight to twelve
repetitions per exercise.
3.7. DATA ANALYSIS
At the completion of the pre- and post test assessment, the data was recorded on a data
sheet in Excel for both the experimental and control groups. Analysis of data was performed
utilizing descriptive and inferential statistics through the help of a statistician at the Nelson
Mandela Metropolitan University. Descriptive statistics investigates the mean, ranges and
standard deviations of a measure to produce more logical, understandable and manageable
information.
According to Gravetter and Wallnua (1995:62) the advantage of using the mean is that it can
be algebraically manipulated and is also a better estimate of the population mean than other
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measures of central tendency. According to Warrack and Keller (1997:106), by far the most
popular and useful measure of central location is the arithmetic mean. The mean was used in
this study to calculate the average for the dependent variables of overall postural stability
indexes, anterior-posterior and medial-lateral stability changes in computer users as
measured in the pre- and post tests, respectively. The standard deviation of a set of
measurements is the positive square root of the variance of the measurements (Warrack and
Keller, 1997:123).
Further investigations utilized inferential statistics to determine the effect of an eight week
Pilates training programme on the dependent variables of postural stability as indicated by the
changes in OSI, API and MLI indexes of computer users.
Significance of results was computed at a p-value of less the 0.05. Analysis of covariance
(ANCOVA) was used in this study. ANCOVA is an extension of ANOVA that typically provides
a way of statistically controlling for the effects of continuous or scale variables, but that is not
the focal point or independent variables in the study (Leech, Barrett and Morgan, 2005:141).
ANCOVA makes all the assumptions of ANOVA as well as those of regression (Dytham,
2003:195). ANCOVA asks the question; if the pre-test scores are held constant, would there
be any significant differences between the post test scores for the experimental and control
group?
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The postural stability test results acquired in this study are shown as an example in Appendix
(G) and the following discussion indicates the interpretation of the statistical data, the format
of which will be used in the discussion of results in chapter four and five, according to The
Biodex Stability System Manual (2000):
1. Stability Level: Indicates the stability of the foot platform. When in a “locked” mode, the
platform is fully stable. A setting of 12 is the most stable and represents the “released”
setting. A setting of one is the least stable foot platform setting. Stability settings of 12
through one allow the foot platform a full 20 degree of deflection from level in any
direction. For participant centering prior to testing, the foot platform deflection is limited
to less that five degrees.
2. Overall Stability Index (IS): Represents the variance of foot platform displacement in
degrees from level, in all motions during a test. A high number is indicative of a lot of
movement during a test with static measures; it is the angular excursion of the
participant’s centre of gravity.
3. Anterior-Posterior Stability Index (AP): Represents the variance of foot platform
displacement in degrees, from level, for motion in the sagittal plane.
4. Medial-Lateral Stability Index (ML): Represents the variance of foot platform
displacement in degrees, from level, for motion in the frontal plane.
5. Standard Deviation: The amount of variability in the statistical measure. A low standard
deviation demonstrates that the range of values from which the mean was calculated
were close together.
6. Percent time in Zone/Quadrant: These values represent the percentage of test time the
participant spends in each Zone/Quadrant during the test.
As indicated in the abovementioned discussion the standard deviation was automatically
calculated by the Biodex Stability System.
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3.8. ETHICAL CONSIDERATIONS
According to De Vos et al. (2002:75), ethics are defined as a set of widely accepted moral
principles that offer rules for and behavioural expectations of the most correct conduct
towards experimental subjects and respondents. To ensure that the study followed adequate
ethical and moral guidelines, permission and approval for the proposed research was sought
from The Human Ethics Committee of the Nelson Mandela Metropolitan University.
The following appendices include relevant information pertaining to ethical considerations of
the study:
Appendix A, B and C was given to each participant explaining the rationale for the research,
what the information will be used for, as well as the participants’ rights. These were given to
the participants in the experimental and control group prior to the commencement of the
study.
The researcher explained and clearly defined the Pilates intervention to the participants
ensuring that the participants knew exactly what the intervention intended to do. Participants
were verbally informed that their involvement in the research study was voluntary and that
he/she may withdraw from the research study at any time without being unfairly discriminated
against.
All information was treated with confidentiality and only the general conclusions were made
public. The participants’ identity with reference to the test results was upheld. Confidentiality
was explained and participants were treated with professionalism. On completion of the eight
week Pilates programme, the control group was offered the opportunity to participate in the
intervention programme, as participation in the Pilates programme could possibly have been
the initial reason for voluntary participation in the study.
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3.9. SUMMARY
This study employed an exploratory, descriptive, quasi-experimental design with a non-
equivalent group approach to evaluate the effect of an eight week Pilates intervention
programme on the postural stability of computer users; and to assess the overall stability
index, the anterior-posterior, and the medial-lateral stability indexes, prior to and after the
implementation of the mat based Pilates programme. A test retest design incorporating an
experimental and control group was used, where participants were matched paired based on
the scores obtained for the dependent variables, following completion of the initial
assessment.
The participants were volunteer computer users selected by means of non-probability
convenience and snowball sampling. All participants were sedentary at the onset of the study
and regarded as being at a beginner level.
The Biodex Stability System (950-304) was used to measure the dependent variables of
postural stability and challenges a participants’ balance while standing on a movable platform
that tilts to a maximum of twenty degrees in different directions. The system uses a
mechanical system which ranges from level one to level eight, where level one represents the
greatest instability. Analysis of data was performed utilizing descriptive and inferential
statistics.
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CHAPTER 4: RESULTS AND DISCUSSION
4.1. Introduction
4.2. Anthropometrical Analysis
4.3. Overall Postural Stability Index Scores Pre- and Post- the Pilates Intervention
Programme
4.4. Anterior-posterior and Medial-Lateral Postural Stability Scores
4.5. Measures of Dispersion
4.6. Summary
4.1. INTRODUCTION
Pilates can be used to improve muscular symmetry and in turn aid in the adjustment of
musculature imbalances while sitting for extended amounts of time. Learning to use the body
correctly and working in alignment helps to achieve greater muscular symmetry because
imbalances are rectified (Kimberly and Katherine Corporation, 2002:2). The purpose of this
study was to determine the impact of a Pilates training programme on the postural stability of
computer users in the workplace.
Data was gathered from the participants prior to and after the eight week Pilates intervention
programme. This data was furthermore processed and analyzed in order to describe the
effect of the intervention programme on the postural stability in computer users.
Analysis of data was performed utilizing descriptive and inferential statistics. According to
Warrack and Keller (1997:106) by far the most popular and useful measure of central
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tendency is the arithmetic mean. Measures of variability or dispersion of data were analysed
and recorded in terms of variances and standard deviations. According to Warrack and Keller
(1997:120) variance is one of the two most widely accepted measures of the variability of a
set of quantitative data (the other is standard deviation). The same authors confirm that
variance and standard deviation are closely related and take into account all the data in a set;
and are of fundamental importance in statistical inference.
According to Warrack and Keller (1997:4) inferential statistics is a body of methods used to
draw conclusions or inferences about characteristics of populations based on sample data. In
order for the statistics to be significant they have to be practical; therefore the experimental
group must be different to the control group post intervention. Compensation was made for
both the experimental and control groups’ initial performance overall stability index (as the
sample was not identical).
As suggested by Gravatter & Wallnau (2005) the indexes were tested at a 95% level of
probability (p<0.05). It must be noted that where p-values were reported as 0.000 it does not
imply that it is equal to zero, it means that it is less that 0.0005.
In order to address the aim of the study, as in Chapter 1, the following objectives were
explored statistically:
• To assess and describe the overall postural indexes,
• To assess and describe the anterior-posterior postural indexes,
• To assess and describe the medial-lateral postural indexes.
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4.2. ANTHROPOMETRICAL ANALYSIS
Descriptive statistics investigate the means, ranges and standard deviations of a measure to
produce more logical, understandable and manageable information.
According to Gravatter and Wallnau (2005) the advantage of using the mean is that it can be
algebraically manipulated and is also a better estimate of the population mean than other
measures of central tendency.
The sample in this study included male and female computer users undergoing Pilates as an
intervention programme. Forty healthy male and female participants volunteered to
participate. The forty participants were divided equally amongst the experimental (Exp) and
control (Con) groups.
However three participants in the experimental and the control group respectively did not
complete the study, due to time constraints. This meant that the study experienced a 15%
drop-out rate.
Descriptive data are exhibited in table 1.
Table 1 below shows that the total number of participants who participated in this study was
34. The mean age of the participants was 39.32 years. The oldest participant tested was 59-
years-old, whereas the youngest was 25-years-old. The median age of the sample was 39.5
years the standard deviation was 9.83. The first quartile represented an average age of 31
while the 3rd quartile represented an average age of 46 years. The minimum height of (1.00)
refers to 151 – 165cm and the maximum height (2.00) refers to 166+cm tall. The height was
used in accordance with the Biodex Stability System Manual.
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Table 1: Descriptive Data of the Control and Experimental Group
N 34 Statistics Con Exp Height Age (yrs) N 17 17 34 34 Mean 39.32 SD 9.83 Minimum 1.00 2.00 1.00 25.00 Median 39.50 Maximum 59.00 2.00 3.00 2.00
Key: Con – Control Group
Exp – Experimental group
Please note that the descriptive data i.e. quartiles, medians and height, were provided by the
researcher for the reader to gain for further insight of the sample and not for analytical
research.
4.3. OVERALL POSTURAL STABILITY INDEX SCORES PRE- AND POST- THE PILATES PROGRAMME
The Biodex system provides an overall stability index (OI) that represents the variance of the
foot platform displacement in degrees, from a level position, in the anterior-posterior (AP) and
medial-lateral (ML) directions during the test.
The participants’ overall index, anterior-posterior, and medial-lateral scores were measured
by the Biodex system.
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Table 2 and 3 showed an overall positive improvement in postural stability; however the mean
score obtained for the experimental group of 0.43 is clearly higher than the 0.29 value
achieved by the control group.
Table 2: Pre- and Post-Test Postural Stability Indexes of Experimental Group
Statistics OI-ae API-ae MLI-ae OI-be API-be MLI-be OI-de API-de MLI-de N 17.00 17.00 17.00 17.00 17.00 17.00 17.00 17.00 17.00 Mean 0.99 0.75 0.56 0.56 0.40 0.30 -0.43 -0.35 -0.26 SD 0.55 0.46 0.30 0.22 0.20 0.14 0.42 0.41 0.26 Minimum 0.40 0.20 0.20 0.30 0.20 0.10 -1.50 -1.20 -0.90 Median 0.90 0.60 0.50 0.50 0.40 0.30 -0.30 -0.20 -0.20 Maximum 2.30 1.70 1.40 1.00 0.90 0.60 -0.10 0.00 -0.10 a: Pre-Test, b:Post-Test, e:Experimental Group, d:Difference;
Table 3: Pre- and Post-Test Postural Stability Indexes of Control Group
Statistics OI-ac API-ac MLI-ac OI-bc API-bc MLI-bc OI-dc API-dc MLI-dc N 17.00 17.00 17.00 17.00 17.00 17.00 17.00 17.00 17.00 Mean 1.25 0.94 0.68 0.96 0.68 0.51 -0.29 -0.25 -0.16 SD 0.96 0.74 0.49 0.51 0.38 0.29 0.55 0.43 0.30 Minimus 0.50 0.30 0.20 0.40 0.20 0.10 -2.00 -1.40 -1.20 Median 0.90 0.70 0.50 0.90 0.70 0.40 -0.10 -0.10 -0.10 Maximum 4.20 3.10 2.20 2.20 1.70 1.10 0.30 0.20 0.20 a: Pre-Test, b:Post-Test, c:Control Group, d:Difference
Key:
OI – Overall Postural Stability Index
API – Anterior-Posterior Stability Index
ML – Medial-Lateral Stability Index
SD – Standard Deviation
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The control group experienced an overall improvement in postural stability. The mean overall
postural stability score of 0.29 was the largest improvement, followed by the anterior-posterior
postural stability mean score improvement of 0.25 and lastly the medial-lateral postural
stability mean score improvement of 0.16 after the post-test.
Based on the statistics in table 2 and 3, figure 1 represents the pre- and post test mean
scores of the overall postural stability indexes for the experimental (Exp) group and control
(Con) group respectively. The following information was derived;
The experimental (Exp) group recorded a pre-test overall postural stability score of 0.99 (OI-
ae) and a post-test mean score (OI-be) of 0.56, the control (Con) group recorded a pre-test
overall postural stability score of 1.25 (OI-ac) and a post test mean score (OI-bc) of 0.96, the
overall postural stability index score of the experimental group improved by 0.43 (OI-de) and
the control group (Con) improved by 0.29 (OI-dc) from the pre-test to the post-test.
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Figure 1: Pre- and Post-test Mean Postural Stability Overall Index Scores
These scores were furthermore interpreted statistically using ANCOVA. ANCOVA is used
when the researcher wants to neutralize the effect of a continuous independent variable in the
experiment. If any variables are known to influence the dependent variable being measured,
then ANCOVA is ideally suited to remove the bias of these variables (Field, 2005:364).
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In this study the following independent variables were compensated for in the overall postural
stability indexes summarized in 4.3, the anterior-posterior and medial-lateral postural stability
indexes summarized in 4.4.
(1) Relationship between the ages of the experimental group pre-test and the control
group pre-test (Age),
(2) Relationship between experimental group pre-test and the control group pre-test (OI
Pre-Test),
(3) Relationship between the height of the experimental group pre-test and the control
group pre-test (Height),
(4) Relationship of the experimental groups’ height pre-test and control groups’ height pre-
test (ExpCon*Height).
All of these extraneous variables had pre-test effects but ANCOVA was used to control for
them. The p-value measures how much statistical evidence exists, so that it can be weighed
in relation to other factors (Warrack and Keller, 1997:346). A p-value less that 0.05 shows that
there is a significant statistical difference between the experimental and control group.
Table 4: ANCOVA results for the post-test Overall Postural Stability Index of the Experimental
and Control Groups
F p (d.f.=1,
28) eta-squared
Overall Index (OI) Age 0.03 0.859 n.a. OI Pre-Test 66.91 0.000 0.7 ExpCon 20.16 0.000 0.42 Height 2.31 0.139 n.a. ExpCon*Height 2.56 0.121 n.a. ANCOVA F = 20.16 p < 0.05 Eta² = .42
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ANCOVA revealed that there was a statistically significant difference (p<0.05) between the
overall stability (OI) post-test scores of the experimental and control groups (ExpCon).
According to Gravatter and Wallnau (2005:233) eta-squared demonstrates the practical
significance of the intervention programme. Eta-Squared interpretation used below is
represented in the following table and will be used consistently with interpretations:
Table 5: Interpretation of Practical Significance of the Intervention
0.01 < r² < 0.09 Small Effect of Intervention/Small Practical Significance of Treatment. 0.09 < r² < 0.25 Medium Effect of Intervention/Medium Practical Significance of
Treatment. r² > 0.25 Large Effect of Intervention/Large Practical Significance of Treatment.
Eta² analysis results confirmed that the Pilates intervention had a practically significant (Eta² >
0.25) impact on post-test overall stability experimental scores.
4.4. ANTERIOR-POSTERIOR AND MEDIAL-LATERAL POSTURAL STABILITY SCORES
Participants scores were calculated for the anterior-posterior (AP) and medial-lateral (ML)
directions, which represent the variance of platform displacement for motions occurring in the
sagittal and frontal planes, respectively.
Based on the statistics in table 2 and 3, figure 2 represents the pre- and post test mean
scores of the anterior-posterior indexes for the experimental (Exp) group and control (Con)
group respectively. The following information was derived:
(1) The experimental group (Exp) recorded a pre-test anterior-posterior score (API-ae) of
0.75 and post test mean score (API-be) of 0.4,
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(2) The control (Con) group recorded a pre-test anterior-posterior score of 0.94 (API-ac)
and a post test mean score (API-bc) of 0.68,
(3) The anterior-posterior postural stability index score of the experimental group improved
by 0.35 (API-de) and the control group improved by 0.25 (API-dc) from the pre-test to
the post-test.
Figure 2: Pre- and Post-test Mean Postural Stability Anterior-Posterior Scores
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Table 6: ANCOVA results for the post-test Anterior-Posterior Postural Stability Index of the
Experimental and Control Groups
F p (d.f.=1,
28) eta-
squared Anterior-Posterior Index (API) Age 0 0.979 n.a. API Pre-Test 34.45 0 0.55 ExpCon 11.18 0.002 0.29 Height 0.93 0.344 n.a. ExpCon*Height 1.4 0.247 n.a. ANCOVA F = 11.18 p < 0.05 Eta² = .29
The significant difference in table 6 highlights the effect of the Pilates intervention in improving
the anterior-posterior stability of the participants as measured on the Biodex. Table 6 shows
the two groups as being statistically different as p = 0.002 (p < 0.05). Eta² showed that the
Pilates intervention was practically significant as Eta² > 0.25.
Based on the statistics in table 2 and 3, figure 3 represents the pre- and post test mean
scores of the medial-lateral indexes for the experimental (Exp) group and control (Con) group
respectively. The following interpretation was deducted:
(1) The experimental group recorded a pre-test medial-lateral score (MLI:ae) of 0.56 and
post test mean score (MLI:be) of 0.30,
(2) The control group recorded a pre-test medial-lateral score of 0.68 (MLI-ac) and a post
test mean score (MLI:bc) of 0.51,
(3) The medial-lateral postural stability index score of the experimental group improved by
0.26 (MLI-de) and the control group improved by 0.16 (MLI-dc) from the pre-test to the
post-test.
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Figure 3: Pre- and Post-test Mean Postural Stability Medial-Lateral Scores
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Table 7 below shows that there is a statistical significant difference between the two groups p
= 0.002 (p < 0.05). Eta² showed that the Pilates intervention was practically significant as Eta²
> 0.25.
Table 7: ANCOVA results for the post-test Medial-Lateral Postural Stability Index of the
Experimental and Control Groups
F p (d.f.=1,
28) eta-
squared Medial-Lateral Index (MLI) Age 0.1 0.750 n.a. MLI Pre-Test 25.33 0.000 0.47 Con 11.83 0.002 0.3 Height 1.87 0.182 n.a. Con*Height 1.57 0.220 n.a.
ANCOVA F = 11.83 p < 0.05 Eta² = .30
4.5. MEASURES OF DISPERSION
Measures of dispersion were measured by the Biodex System for each participant. The
measures of dispersion were used and analysed as a supplement to the overall, anterior-
posterior and medial-lateral scores shown above. A decrease in scores over three
consecutive trials measured pre- and post intervention is seen as favourable. An increased
displacement from the centre point of the Biodex platform is displayed as a higher score
(which is unfavourable).
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Figure 4: Pre- and Post-Test Measures of Dispersion
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Resulting measures of overall postural stability dispersion scores are shown graphically
above in Figure 4. The experimental group recorded a pre-test overall measure of dispersion
score of 0.88 (OI:ae) and a post-test measure of dispersion mean score (OI:be) of 0.34. The
control group recorded a pre-test overall measure of dispersion score of 0.92 (OI:ac) and a
post-test measure of dispersion mean score (OI:bc) of 0.65. The overall measure of
dispersion score of the experimental group improved by 0.53 (OI:de) and the control group
improved by 0.27 (OI:dc).
Table 8: ANCOVA results for Overall, Anterior-Posterior and Medial-Lateral post-test
Measures of Dispersion for the Experimental and Control Groups
F p (d.f.=1, 28) eta-squared
Overall Index (OI_SD) Age 2.68 0.113 n.a. OI Pre-Test 15.74 0.000 0.36 ExpCon 14.98 0.001 0.35 Height 2.65 0.115 n.a. ExpCon*Height 4.27 0.048 0.13 ANCOVA F = 14.98 p < 0.05 Eta² = .35 Anterior-Posterior Index (API_SD) Age 1.22 0.279 n.a. API Pre-Test 18.48 0.000 0.40 ExpCon 14.44 0.001 0.34 Height 3.33 0.079 0.11 ExpCon*Height 3.91 0.058 n.a.
ANCOVA F =14.44 p < 0.05 Eta² = .34 Medial-Lateral Index (MLI_SD) Age 4.32 0.047 0.13 MLI Pre-Test 19.54 0.000 0.41 ExpCon 15.52 0.000 0.36 Height 0.83 0.371 n.a. ExpCon*Height 2.97 0.096 n.a. ANCOVA F = 15.52 p < 0.05 Eta² = .36
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Table 8 above revealed the analysis of covariance ANCOVA as having a statistically
significant difference between the two groups p = 0.001 (p < 0.05). It also reveals that the
anterior-posterior and medial-lateral both had statistically significant differences of 0.001 and
0.000 respectively. Eta² showed that the Pilates intervention was practically significant as Eta²
> 0.25 in all three overall, anterior-posterior and medial-lateral indexes (refer table 2 for
interpretation).
Table 9: Pre- and Post-Test Measures of Dispersion of the Experimental Group
MD:Statistics OI-ae API-ae MLI-ae OI-be API-be MLI-be OI-de API-de MLI-de N 17 17 17 17 17 17 17 17 17 Mean 0.88 0.81 0.58 0.34 0.32 0.25 -0.53 -0.48 -0.33 SD 0.76 0.72 0.31 0.18 0.17 0.11 0.7 0.67 0.25 Minimus 0.19 0.23 0.18 0.12 0.14 0.09 -2.69 -2.55 -0.84 Median 0.55 0.45 0.49 0.28 0.28 0.24 -0.19 -0.19 -0.31 Maximum 3.12 2.98 1.29 0.74 0.72 0.45 -0.16 -0.09 -0.15 a: Pre-Test, b:Post-Test, e:Experimental Group, d:Difference
A score difference of overall stability indexes of the measures of dispersion is shown as 0.53
in the above table 9. The table also shows a score difference of anterior-posterior measures
of dispersion as 0.48 and finally a score difference of medial-lateral dispersion of 0.33. The
experimental group had more of an anterior-posterior dispersion than a medial-lateral
dispersion as indicated by the difference of 0.15 (subtract 0.33 from 0.48).
Table 10: Pre- and Post-Test Measures of Dispersion of the Control Group
MD:Statistics OI-ac API-ac MLI-ac OI-bc API-bc MLI-bc OI-dc API-dc MLI-dc N 17 17 17 17 17 17 17 17 17 Mean 0.92 0.88 0.62 0.65 0.6 0.46 -0.27 -0.28 -0.15 SD 0.72 0.76 0.4 0.44 0.4 0.29 0.48 0.49 0.29 Minimus 0.32 0.27 0.21 0.15 0.15 0.12 -1.53 -1.67 -0.97 Median 0.66 0.63 0.44 0.45 0.43 0.34 -0.19 -0.19 -0.1 Maximum 3.12 3.26 1.73 1.59 1.59 1.19 0.49 0.35 0.3 a: Pre-Test, b:Post-Test, c:Control Group, d:Difference
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A score difference of overall stability indexes of the measures of dispersion is shown as 0.27
in the above table. The table also shows a score difference of anterior-posterior measures of
dispersion as 0.28 and finally a score difference of medial-lateral dispersion of 0.15. The
control group had more dispersion anterior-posteriorally than medial-laterally as indicated by
the difference of 0.13 (subtract 0.15 from 0.28).
4.6. SUMMARY
The aim of the study was to determine the impact of a Pilates training programme on the
postural stability of computer users in the workplace. The objectives of the study were used to
assess and describe the overall stability, anterior-posterior and medial-lateral indexes pre-
and post the eight week mat based Pilates intervention programme
Statistically the study showed that there was a difference between the pre and post-test of the
experimental group, the pre and post-test of the control group, but more importantly there was
a statistical and practical difference between the post-tests of both the experimental and
control group.
Statistically the mean overall postural stability score of 0.43 indicated the highest
improvement, followed by the anterior-posterior postural stability mean score improvement of
0.35, and a 0.26 improvement of the medial-lateral postural stability mean score post the
Pilates intervention programme.
ANCOVA concluded that the following relationships did not play a role in the treatment
results:
• the ages of the experimental group pre-test and the control group pre-test,
• the experimental group pre-test and the control group pre-test,
• the height of the experimental group pre-test and the control group pre-test,
• the experimental groups’ height pre-test and control groups’ height pre-test
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The Pilates intervention programme proved to be practically significant. The eta-squared
results showed that the size of the treatment effect for all three postural stability scores was
large (OI: 0.42; API: 0.29; MLI: 0.30). The eta-squared results showed that the size of the
treatment affect for all three measures of dispersion scores was large (OI: 0.35; API: 0.34;
MLI: 0.36).
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CHAPTER 5: CONLUSIONS AND RECOMMENDATIONS
5.1. Introduction
5.2. Effects of Pilates on Work-Related Injuries in Computer Users
5.3 . Effects of Pilates on Postural Stability
5.4. Conclusions
5.5. Limitations and Recommendations
5.1. INTRODUCTION
Based upon the body of evidence presented in the literature overview in chapter 2, and
guided by the research aim relating to the objectives of the study, this chapter now reports on
the outcomes of the statistical analyses of the selected dependent variables of overall
postural stability, anterior-posterior and medial-lateral stability. These findings highlight the
positive effect of the treatment variable, namely, participation in an eight week mat-based
Pilates intervention programme for adult sedentary computer end-users. According to
Rydeard, Leger & Smith (2006:472) the Pilates method is a movement system that
incorporates a conditioning programme that improves muscle control, flexibility, coordination,
strength, and muscle tone. The basic principles underlying the performance of Pilates-based
exercises are to create postural awareness and postural alignment, to enhance movement
integration, to coordinate breathing with exercise performance, and to increase efficiency and
flow of movement.
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5.2. EFFECTS OF PILATES ON WORK-RELATED INJURIES IN COMPUTER USERS
The principal findings of literature on ergonomics and work-related injuries reiterate that the
human body is not designed to be immobile or to perform repetitive movements (Thibodeau,
1995:322). Individuals who work with computers and/or visual display terminals lead a
sedentary working lifestyle and this type of work lends itself to constrained postures, which
impart static loads on the neck and entire spine, including the lower back, as well as the
shoulders and upper extremities (Waikar and Bradshaw, 1995:16). Sjőgaard (1990:1) states
that because there is insufficient research on poor posture in the workplace, the result will
manifest in the recurrent form of a chronic syndrome of pain and musculoskeletal injuries.
Literature clearly provides sufficient evidence of the impact of physical activity and structured
exercises on the reduction of work-related musculoskeletal stress, as a result of changes in
biomechanical loading of the spine, neural mobilisation, enhanced core stability and functional
stability (Johanning, 2000:94; Ose, 2005:161; Pope et al. 2002:49; Press cited in Brukner and
Khan, 2007:357).
A plethora of evidence in the acquired literature furthermore demonstrates the importance of
an effective intervention programme, such as Pilates, to combat the epidemic of
musculoskeletal disorders. Epidemiological studies indicated that low back pain was one of
the most widely experienced health-related problems in the world as it affected up to 85% of
the population at some time of their lives (Simmonds & Dreinsinger in Durstine & Moore,
2003:217; Press cited in Brukner & Khan, 2007:352). Although the authors reported that back
pain improved over a three-month period in the vast majority of incidences, nearly 50%
presented with at least one recurrent episode. The authors alarmingly reported low back pain
to be the most common disability in those under the age of 45 and posed the most expensive
health care challenge in those between the ages of 20- to 50- years.
The multidimensional nature of this chronic condition with a tendency to reoccur, contributed
to a large portion of work absenteeism, a resultant loss of productivity and ultimately imposing
a significant economic burden on health systems as well as inflicting great costs on society at
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large (Bull, Pratt, Shepard and Lankenau, 2006:127). Although official figures could not have
been accessed in the processing of this dissertation, an estimated cost to the economy of
South Africa for chronic low back pain amounted to more than R2 billion in 1999 (Belot,
2005). According to the Belot (2005) the estimated figure grew to R6 billion in 2002.
Active rehabilitative intervention programmes should be included as a problem management
approach to address postural-related musculoskeletal disorders of individuals in the
workplace. Hubley-Kozey and Vezina (2002:1106) and Hodges (2003:245) stated that
exercises to improve trunk stability reduced the intensity of associated pain, alleviated
functional disability, and improved back extension strength, mobility and endurance.
Considerable evidence exists pertaining to the role that the trunk muscles play in stabilizing
the spine, in addition to the essential role played by the transversus abdominis and lumbar
multifidus muscles (Hodges, Eriksson, Shirley & Gandevia, 2003:1873; Muscolino & Cipriani,
2004: 18; Press cited in Brukner and Khan, 2007:375).
Spinal stabilization exercises have been a well documented in the management of low back
pain over the last decade. Pilates as an alternative method of intervention utilises spinal
stabilisation exercises as one of the fundamental principles of movement performance and
subsequently proved to be effective in combating the epidemic of musculoskeletal disorders
due to a sedentary occupation. Mannion, Kaser, Webber, Rhyner, Dvorak & Muntener
(2000:273) and Mannion, Muntener, Taimela & Dvorak (2001:772) ascribed weakness in the
paraspinal muscles to histo-morphologic and structural changes which occur due to type II
muscle fiber atrophy as a result of disuse and deconditioning. Therefore, part of the
significance of this study was embedded in utilising Pilates as a method of intervention to
address and restore the structural and functional postural related weaknesses and
impairments that is an inherent condition in sedentary occupations, such as in end- computer
users.
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5.3. EFFECTS OF PILATES ON POSTURAL STABILITY
Kendall, McCreary, Provance, Rodgers and Romani (2005:59) define a good posture as a
state of muscle and skeletal balance which protects the supporting structures of the body
against injury or progressive deformity. Under such conditions the muscles will function more
efficiently and the optimum positions are afforded for the thoracic or abdominal regions.
According to the authors, thoracic kyphosis is known to alter the shape of the thoracic cage,
decrease the anterior-posterior diameter of the thorax, thus reducing the distance between
the xiphisternum and pubis, and alter the position of the ribcage so that it surrounds the
abdominal cavity.
Postural stability can be assessed through the limits of stability and limits of stability can be
defined, under dynamic conditions, as “the maximum displacement of the center of body
mass during a feet-in-place response to external postural perturbations that can be controlled
without a fall or a step” (Mancini, Rocchi, Horak and Chiari, 2008:450). Control of body
segments is needed for the coordination and production of anticipatory adjustments that
would counteract the critical perturbations of posture (De Nunzio, Nardone and Schieppati,
2007:258).
Brukner and Khan (2007:163) emphasized the importance of trunk muscle strength, muscle
control, muscle endurance and patient education in the performance of Pilates stabilisation
exercises. The Pilates exercise intervention programme utilised in this study includes the
before mentioned components. Furthermore a core body of evidence explored Pilates as an
effective and efficient intervention programme for low back pain. Anderson, Butler and Roach
(2006) used a six week randomised control trial to examine whether subjects with chronic low
back pain or recurrent low back pain improved on pain and disability measures. The results
demonstrated greater improvements with regards to pain and disability in the Pilates groups
than in the massage groups. The same authors concluded that the Pilates method therefore
improves low back pain and is an effective mode of rehabilitation for persons with low back
pain. La Touche, Escalante and Linares (2007) conducted a systematic review to analyse
specific articles where the Pilates method was used as treatment for non-specific low back
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pain. The studies chosen were clinical trials and randomised control trials. All the studies
under investigation supported each other by displaying positive results when using the Pilates
method as exercise intervention for persons with low back pain. The studies showed effects,
such as improved general function and reduction in pain, when applying the Pilates method.
One of the aims of the study was to determine whether the Pilates intervention would cause
any changes in the anterior-posterior and medial-lateral stability scores. The Pilates
intervention programme addressed the musculo-skeletal symmetry and range of motion whilst
increasing the extensibility of the relevant muscles and connective tissue. Tortora (2005:259)
proposed that an additional benefit of the Pilates programme which includes flexibility reduced
the effects of gravitational forces acting on the body and improper posture due to incorrect
alignment of soft tissues, hence acting to improve and maintain good posture.
The body of evidence confirms that overall postural stability, anterior-posterior postural
stability and medial-lateral postural stability improved.
5.4. CONCLUSIONS
The rationale of the study to determine the effects of the Pilates intervention programme on
computer users yielded significant positive results in the overall, anterior-posterior and
medial-lateral postural stability indexes. The quantitative data analysed in this study has
become a very useful tool outlining the relevance of a Pilates exercise programme designed
for postural awareness. The steady rise of work disabilities relating to neck and lower back
pain continues to burden both the employer and employee. The role of postural education
should not be underestimated and maintenance thereof should be incorporated in everyday
functioning. This should become the responsibility of both the employer and employee in
future postural awarenesss and pain management.
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5.5. LIMITATIONS AND RECOMMENDATIONS
In all studies there are a number of factors that limit the outcome or have an effect on the
study’s results. The following limitations could have had an impact on the results obtained in
the study.
The relative small sample size based on sedentary volunteer end computer users and more
importantly, the restricted use of beginner level mat-based exercises only, without being able
to progress to intermediate and advanced level of Pilates exercises, posed to be a challenge
for the researcher. Furthermore, having access to more than one Pilates instructor to train a
group of four participants at one session should address the problem at hand and therefore
increase the reliability and validity of the outcomes of the study. Also diversity of the level of
Pilates taught.
Due to the time constraints on behalf of the participants, who had to fit the sessions into their
lunch hour break and traveling to the Pilates venue, an eight week intervention period was
followed. Ideally, an extended duration of at least 12 weeks of Pilates intervention training
should be followed to obtain more specific and reliable results to bridge the gap in
documented evidence of the long-term effect of Pilates training on the human body.
Longitudinal studies were also lacking in the literature retrieved.
A further limitation was the diverse sample age range which could have influenced the
physiological response to the Pilates exercises. An investigation into the age-related
physiological responses to Pilates exercises would be an interesting study to pursue.
During this study there was consistent positive feedback from the participants post the
intervention programme. A further recommendation for future studies would be the exploration
of the research participants’ experience of the Pilates.
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To summarize, the suggestions for further research would be as follows:
• To explore and describe the effects of a Pilates intervention programme using a larger
sample size,
• To determine the effects of a Pilates intervention programme on homogenous age
groups of a specific gender,
• To explore and describe the effects of a 12-week Pilates intervention programme on
other selected health-related dependent variables, such as functional core strength,
upper and lower body strength, as well as flexibility,
• To determine the effects of using the Pilates reformer as specialized equipment as a
Pilates specific training method on aforementioned selected variables, and
• To explore and describe psychosocial outcome measures for those with low back pain
being treated with Pilates as a method of intervention.
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Appendix A: INFORMATION AND INFORMED CONSENT FORM
Title of the research project Pilates for Postural Stability in Computer Users.
Principal investigator Lana Strydom Address 143 River Road Walmer Postal Code Port Elizabeth 6070 South Africa Contact telephone number 722562042
A. DECLARATION BY OR ON BEHALF OF PARTICIPANT: Initial I, (the undersigned), ______________________________ (name) I.D.No._______________________________________________ OR I, in my capacity as _________________________ (relationship) of the participant ___________________________ (name) I.D. No. ______________________________________________ of ___________________________________________________ ____________________________________________(address)
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A.1. I HEREBY CONFIRM AS FOLLOWS: Initial 1. I, the participant, was invited to participate in the above mentioned research project which is being undertaken by Lana Strydom of the Department of Human Movement Science in the Faculty of Health Science at the NMMU.
2.2. Procedures: I understand that I will be tested on the Balance Biodex System at the NMMU in June and again in September 2007
2.3. Risks: N/A
2.4. Possible Benefits: As a result of my participation in this study I will have my postural stability recorded on the Balance Biodex Balance System at the NMMU.
2.5. Confidentiality: My identity will not be revealed in any discussion, description or scientific publications by the principle investigators.
2.6. Access to findings: Any new information/or benefit that develops during the course of the study will be shared as follows: via email or telephone.
2.7 Voluntary participation/refusal/discontinuation:
My participation is voluntary:
My decision whether or not to participate will in no way affect my present or future medical care/employment/lifestyle:
Yes
Yes
No
No
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3. The information above was explained to me/the participant by Lana Strydom in English and I am in command of this language and I was given the opportunity to ask questions and all these questions were answered satisfactorily.
4. No pressure was exerted on me to consent to participation and I understand that I may withdraw at any stage without penalisation.
5. Participation in this study will not result in any additional cost to myself.
A.2. I HEREBY VOLUNTARILY CONSENT TO PARTICIPATE IN THE ABOVE MENTIONED PROJECT: Initial
Signed/confirmed at ___________________________ (place)
on _________________________________ 2007.
Signature of participant: __________________________________
Signature of witness: ___________________________________
Full name of witness: ___________________________________
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B. STATEMENT BY INVESTIGATOR: Initial I, Lana Strydom, [I.D.No. 8308030251085], declares that
I have explained the information in this document to __________________________________________ (participant);
He/She was encouraged and given ample time to ask me any questions;
This conversation was conducted in English and Afrikaans where necessary.
I have detached Section C and handed it to the participant: Initial
Signed at _____________on _________________ 2007 Signature of investigator ________________________________
Signature of witness ____________________________________ Full name of witness ____________________________________
C: IMPORTANT MESSAGE TO PARTICIPANT: Initial Dear Participant, Thank-you for your participation in this study. Should, at any time, during the study, an emergency arise as a result of the research, or you require further information with regard to the study,
Kindly contact Lana Strydom at 0722562042.
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Department of Human Movement science
Faculty of Health Sciences
Tel: +27 (0) 41 504 2128
June 2007
Appendix B: LETTER TO EACH PARTICPANT IN THE EXPERIMENTAL GROUP
Dear Participant
You are being asked to participate in a research study. We are going to give you information that will help you understand, its purposes and its aims. It will also explain what you will be asked to do during the study, the risks and the benefits, and your rights as a participant in this research study. If anything is not clear please feel free to ask the researcher to clarify it to you.
You will be asked to give your approval in the form of a written consent that will include your signature, date, and initials to verify that you understand and agree with the conditions pertaining to the research project.
You reserve the right to ask questions concerning the research study at any time. It would be appreciated if you could immediately report to the researcher any problems you may have during the study. Please call the number listed below or simply email the researcher with any further queries or worries.
The Human Resources Ethics Committee (HREC) has approved this research study at the NMM University. The HREC is a group of independent experts whose responsibility is to help and ensure that the right to health and welfare of the participants in research are protected and that the study is carried out in an ethical manner. This research study cannot be conducted without the HREC approval. If you would like to contact the HREC with any further questions please contact the Research Management at (041) 504 4536.
Participation in research is completely voluntary. You are not obliged to take part in research, and if you choose not to participate, your present and/or future medical care will not be affected in any way. You will also not incur a penalty and/or loss of benefits to which you may be otherwise entitled.
If you agree to partake in the research study, you have the right to withdraw at any given time, during the study without penalty or loss of benefits. However, if you do withdraw, you should return for the final discussion in order to terminate the research in an orderly manner.
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The nature of the research study that you will be involved in is an experiment with a group of adults. We will measure your postural stability using the Biodex Balance Stability System. Thereafter, an 8 week Pilates training programme will be provided to you, which you will need to comply with throughout the study. Your postural stability will again be evaluated after the Pilates training programme to measure any fluctuations.
The improved posture, after the Pilates training programme, will positively aid in developing a strong muscular system in the stomach area. The Pilates training programme should have a positive effect on your posture while seated at the computer for many hours of each week. In a technological working environment posture will become the essence to better performance levels.
This informed consent has been prepared in accordance with current Medical Research Council guidelines. Please remember that this study can be terminated at any time by the researcher or the HREC that initially approved it.
Please feel free to contact me at any time during this research study!
Yours Faithfully
Lana Strydom
0722562042
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Department of Human Movement science
Faculty of Health Sciences
Tel: +27 (0) 41 504 2128
June 2000
Appendix C: LETTER TO EACH PARTICIPANT IN THE CONTROL GROUP
Dear Participant
You are being asked to participate in a research study. We are going to give you information that will help you understand, its purposes and its aims. It will also explain what you will be asked to do during the study, the risks and the benefits, and your rights as a participant in this research study. If anything is not clear please feel free to ask the researcher to clarify it to you.
You will be asked to give your approval in the form of a written consent that will include your signature, date, and initials to verify that you understand and agree with the conditions pertaining to the research project.
You reserve the right to ask questions concerning the research study at any time. It would be appreciated if you could immediately report to the researcher any problems you may have during the study. Please call the number listed below or simply email the researcher with any further queries or worries.
The Human Resources Ethics Committee (HREC) has approved this research study at the NMM University. The HREC is a group of independent experts whose responsibility is to help and ensure that the right to health and welfare of the participants in research are protected and that the study is carried out in an ethical manner. This research study cannot be conducted without the HREC approval. If you would like to contact the HREC with any further questions please contact the Research Management at (041) 504 4536.
Participation in research is completely voluntary. You are not obliged to take part in research, and if you choose not to participate, your present and/or future medical care will not be affected in any way. You will also not incur a penalty and/or loss of benefits to which you may be otherwise entitled.
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If you agree to partake in the research study, you have the right to withdraw at any given time, during the study without penalty or loss of benefits. However, if you do withdraw, you should return for the final discussion in order to terminate the research in an orderly manner.
The nature of the research study that you will be involved in is an experiment with a group of adults who make use of computers in their everyday work setting. We will measure your postural stability using the Biodex Balance Stability System, and after an 8 week period we will retest on the same System.
The tests used to measure your postural stability are easy and will not harm you in any way. These tests will provide you with the insight of your postural stability, as well as motivating you towards engaging in a Pilates training programme to improve your everyday work experiences.
This informed consent has been prepared in accordance with current Medical Research Council guidelines. Please remember that this study can be terminated at any time by the researcher or the HREC that initially approved it.
Please feel free to contact me at any time during this research study!
Yours Faithfully
Lana Strydom
0722562042
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Appendix D: PROTOCOLS FOR PERFORMING A POSTURAL STABILITY TEST
1. Position the support handles as per patient protocol.
2. Position display height and tilt for patient comfort.
3. At the Main Menu, touch <testing>. The Testing Menu screen should now be displayed
4. Touch <Postural Stability>. The user Setup Information screen should now be
displayed.
5. Touch the <Keypad> icon for the “Name” and enter the participant’s name. Touch
<OK> to return to the User Setup information screen.
6. Touch the <Keypad> icon for “Age” and then enter the patient’s age. Touch <OK> to
return to the User Setup Information screen.
7. Touch the appropriate <Height> key to highlight the patient height range setting
desired. Touch <Next> to advance to the Patient Position screen.
8. Position the patient on the system and explain the test protocol. Press <Start> on the
display to activate the cursor and have the patient move he cursor to the center point
on the grid.
9. Touch <Record> to bring up the Position Patient Entry screen. Using the keypads,
enter the patient’s left foot, left heel, right foot and right heel positions using the midline
of the foot and the platform grid as reference points. Touch <Next> to advance to the
Postural Stability Testing screen.
10. At the Postural Stability testing screen, touch <Stance> to scroll through the three
stance positions provided: left right or both.
11. Touch <Tracing> to toggle tracing On or OFF as desired.
12. Touch <Clear Tracing> to clear any tracing that remains from previous tests.
13. Touch <More Options> to advance to the Postural Stability Test Options screen if
desired. Here the Time Trial Time is set as 20, Test Trials as 3, Rest Countdown as
10, Platform Settings as 8, and toggle the bilateral comparison to “No”. Touch <OK> to
confirm your selections and return to the Postural Stability Testing screen.
14. Press <Start> to release the platform (if not static) and activate the Postural Stability
Test screen.
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15. With the patient ready to begin the test, touch <Collect Data>. The screen will provide
a three-second countdown before beginning the first of three test trials. The display
screen will show Total Trial Time, Platform Setting and Stance to the left of the grid.
Trial Number and score are displayed to the right of the grid.
16. After completing the tests, a “Test Complete” message is displayed. Touch the
<Results> to advance to the Postural Stability Test Results screen.
17. At the Postural Stability Test Results screen, Touch <Print> to automatically generate
a printed report.
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Appendix E: MECHANICS AND FUNTIONING OF THE BIODEX BALANCE SYSTEM
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Appendix F: PILATES INTERVENTION PROGRAMME
Warm up
Breathing
Imprint and Release
Hip Release
Spinal Rotation
CAT stretch
Hip Rolls
Scapula Isolation
Arm Circles
Head Nods
Elevation and Depression of Scapulae
Exercises
Ab Prep
Breast Stroke Prep 1,2,3
Shell Stretch
Hundred
Half Roll Back
Roll Up
One Leg Circle
Spine Twist
Rolling like a Ball
Single Leg Stretch
Obliques
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Double Leg Stretch prep
Scissors
Shoulder Bridge Prep
Roll Over Prep
One Leg Kick
Breast Stroke
Shell Stretch
Saw
Neck Pull
Obliques Roll Back
Side Kick
Side Leg Lift Series 1,2,3,4,5
Spine Stretch Forward
Single Leg Extension
Swimming
Shell Stretch
Leg Pull Front
Seal
Side Bend
Push UP
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Appendix G: STATISTICAL DATA ON THE BIODEX BALANCE
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