aacpdm ic saturday · saturday, october 19, 2013 ... adaptedfromwoollacott&shumway‐cook,2001...

AACPDM 2013 IC 37 Saturday

Gaebler & Girolami 1

THE FRAMEWORK OF MOVEMENT and IMPLICATIONS FOR CLINICAL PRACTICE

IC 37Saturday, October 19, 2013

1:30 – 3:30

Deborah Gaebler‐Spira, MD

Gay L. Girolami, PT, PhD

Postural Control

involves the control of the body’s position in space in order to obtain stability and orientation

(Massion, 1998)

center of body mass (COM)a location of the net mass of all the

body segments in space

Stability – is the maintenance of the center of body mass (COM) within the base of support during static or dynamic activities

center of pressure (COP)measures the

location of the vertical ground reaction vector at the surface of support

Base of support BOS is the possible range of the center of pressure COP

motion of the COP measured in terms of sway area represents an individual's control of the body sway or preservation of stance stability

Functional Goals of Postural Control

• Postural orientation the active alignment of the trunk and head with respect to gravity, support surfaces, the visual surround and internal references

• Postural equilibrium the coordination of movement strategies to stabilize the centre of body mass during both self‐initiated and externally triggered disturbances of stability



The purposes of that control are tomaintain equilibrium and orientationin sitting and standing

(Horak, 1992; Shumway‐Cook & Woollacott, 1993)

Why this topic is important?

Cerebral Palsy

“Cerebral palsy (CP) describes a group of disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, cognition, communication, perception, musculoskeletal and/or behaviour, and/or by a seizure disorder.”

Bax M, Goldstein M, Rosenbaum P, Leviton A, Paneth N. definition and classification of cerebral palsy,

April 2005. Dev Med Child Neurol 2005;47(8):571‐6.

What drives early postural control

• Combined reduction of equilibrium reactions

• Righting reflexes

• Bleck‐1987‐Of all the motor problems in CP deficient equilibrium reactions interfere the most with functional walking

Postural control

• is no longer considered simply a summation of static reflexes but, rather, a complex skill based on the inter‐ action of dynamic sensorimotorprocesses

Contributors of Postural Control Mechanism

A complex interaction of systems and higher level processes.

Adapted from Woollacott & Shumway‐Cook, 2001

Postural Control

Musculoskeletal components

Sensory Systems

Sensory strategiesNeuromuscular

Synergies

AnticipatoryMechanisms

AdaptiveMechanisms

Internal Representations



Vestibular SystemProprioception

Vision

Strength

Postural Control

Precarious Balance

Alignment

Postural Performance

• Biomechanical constraints‐alignment and spasticity, weakness

• Movement strategies‐selective motor control , praxia

• Postural orientation‐righting, equilibrium

• Sensory environment‐visual, vestibular, proprioception

• Experience‐developmental

• Cognitive resources

“Sensory information from somatosensory, vestibular and visual systems is integrated, and the relative weights placed on each of these inputs are dependent on the goals of the movement task and the environmental context.”

Head Control as Basis

• sensory organs for visual and vestibular

• systems are embedded in the head, making refined head control of critical importance for both orientation and balance

6 Month – Typical Development

6 Month – Atypical DevelopmentPhotos: www. Pathways.org

Vestibular systems

• during posturographythat sensory conditions in which children must rely primarily on vestibular cues cause instability and frequent falling in children with spastic CP

• Liao et al. 1997, 2003;

Deficits of Sensory function

• Tactile, kinesthetic proprioceptive information

• Needed to determine starting position of limb

• Correct errors for refinement of skills

• Neglect‐learned non‐use



Sensory

• Proprioception

• Position sense is altered and biased

• Subjects were asked to place at certain position

• Joint‐Position Sense and Kinesthesia in Cerebral Palsy

• Wingert et al

The amount of cognitive processing required for postural control depends both on the complexity of the postural task and on the capability of the subject’s postural control system.

Alignment

Postural Balance in Children with CPRose, et al

• center of pressure

calculations of path length per second, average radial displacement‐ sway excursion

• force plate evaluation of postural balance can detect impairment of specific components of postural balance

• 1/3 had deficits and the majority deficits were in radial displacement

Walking prognosis in cerebral palsy: a 22‐year retrospective analysis

de Paz Junio, Burnett, Braga

• A retrospective study was performed of 272 patients with spasticity to determine criteria for the prognosis for ambulation based on the ages at which children with cerebral palsy attain important gross motor milestones. The variables analyzed were age at last clinical assessment, clinical type of cerebral palsy and ages at attainment of gross motor milestones. Achievement of head balance before nine months was an important parameter for good prognosis for walking and, after 20 months of age, an indicator for poor prognosis. Sitting by 24 months indicated a favorable outcome, and motor control of crawling at 30 months of age was a predictor for good prognosis. Based on these data, a chart for walking prognosis in children with cerebral palsy is presented.

Dev Med Child Neurology 1994 Feb;36(2):130‐4.



• The control of posture involves many different underlying physiological systems that can be affected by pathology or sub‐clinical constraints

• The effective rehabilitation of balance to improve mobility and to prevent falls requires a better understanding of the multiple mechanisms underlying postural control.

Balance‐treatment options ‐ part two

Efficacy and Effectiveness of Physical Therapy in Enhancing Postural Control in Children with Cerebral

PalsySusan R. Harris and Lori Roxborough

• NEURAL PLASTICITYVOLUME 12, NO. 2‐3, 2005

Virtual reality as a therapeutic modality for children with cerebral palsy

LAURIE SNIDER, ANNETTE MAJNEMER, & VASILIKI DARSAKLIS

• postural control / balance improved during hippotherapy and THR



WiiagnosticsStudying balance and function in cerebral palsy

using video games

Mickey Kopstein, Iris Valeris PHD

2013 RIC Summer Extern

Discussion

• Wii Fit is able to accurately measure parameters related to balance

• More sensitive than traditional measures

• Potential to monitor outcomes accurately at home

• Can diagnose specific problem areas and cater therapy to patient

Compensatory and Anticipatory Postural Control

Postural Control MechanismsMechanism Typical time delay

Anticipatory postural adjustments < 0 ms prior to perturbation

Muscle and tendon elasticity 0 ms

Monosynaptic reflexes 30 ms

Polysynaptic reflexes 50 ms

Compensatory postural reactions(preprogrammed rxns)

70 ms

Voluntary actions 150 ms & onwards

Adapted from Latash 2008

Main Mechanisms of Postural Control

Anticipatory Postural Adjustments (APAs) – Muscle activity prior to the onset of voluntary movement / perturbation

– Feedforward postural control

– Serve to counteract the predicted perturbation

Compensatory Postural Adjustments (CPAs) – Occur after a perturbation

– Triggered by sensory feedback signals – feedback postural control

– Serve to reorganize posture and maintain balance

0 ms

APA CPA

Timeline of APAs and CPAs

‐ 150 ms + 70 ms

Reflex Responses



Postural Control Mechanisms

• CPAs: balance training programs commonly incorporate CPA concept

(i.e., strengthening/strategies for recovering balance, multi direction stepping exercises)

• APAs not well understood/established in terms children and clinical interventions

COMPENSATORY POSTURAL ADJUSTMENTS

Girolami & Shiratori CSM 2010

DEVELOPMENT OF POSTURAL CONTROL IN INFANTS AND CHILDREN

CPAs First Six Months

• A repertoire of variable, but direction specific postural adjustments are seen before independent sitting

– Minimal ability to adapt to the perturbation

– As early as 3‐4 months ability to balance flex/ext of the neck for head control in supported sitting Harbourne et al, 1987

– Inconsistent ability to inhibit dorsal mms (NE, TE) prior to activation of ventral muscles in FW translation (BW sway)

First Six MonthsBy 4 – 5 months successful grasping is accompanied by variable, direction specific patterns

Infants able to adapt muscle activity relative to their position Supine

Semi‐reclined

Upright sitting

Semi‐reclined sitting yields earlier activation of neck flexors and extensors than upright supported sitting

Van der Fits & Hadders‐Algra, 1998

Semi‐Reclined Position in Treatment

The semi‐reclined

position has been

used to increase the

activation of the neck

flexors and develop

improved strength and

balance between neck

flexors and extensors

Girolami & Campbell, 1994



By 6 months

• Infants can begin to select from a repertoire of direction specific patterns of muscle activation

– Able to select patterns of muscle activity in response to the perturbation – forward vs. backward

– Variation of responses decreases with age

– Increased ability to inhibit dorsal mms (NE, Trunk Ext) prior to activation of ventral muscles in FW translation (BW sway)

– Experience increased body awareness shown by ability to choose the best stabilization of the head for the movement paradigm

Van der Fits & Hadders‐Algra, 1998, 1999a

Six to Nine Months

Able to adapt the magnitude of muscle activity in the enbloc pattern to match the degree of perturbation

Coincides with ability to sit independently

Between 6 – 9 months infants increasingly choose the enbloc postural pattern from their repertoire esp. when risk of loss of balance is high

Van der Fits & Hadders‐Algra, 1998, 1999b

From Nine Months Consistent activation of direction specific muscles

Ability to modulate response patterns is present by 9‐10 months in sitting

With respect to velocity of perturbation

With respect to the pelvic position

With respect to load

Fully developed CPAs in sitting at three years

Fully develop adult patterns in standing on translational surfaces between 7‐10 years

Shumway‐Cook and Wollacott, 1985

The postural response pattern is activated based on the direction of the perturbation

– Backward translation of the support surface causes a forward weight shift resulting in activation of the dorsal neck, trunk, lower extremity muscle groups.

– Forward translation of the support surface causes a backward weight shift resulting in activation of the ventral neck, trunk and lower extremity muscles


Postural Strategies• Ankle Strategy – when perturbations are small, distal to

proximal muscle activation is used to maintain posture

• Hip Strategy – when perturbations are large, causing changes in body geometry, proximal to distal muscle activity is recruited

• Stepping strategy – when the external perturbation is too great and limits of stability are exceeded, the individual takes a step to maintain Com within BOS


CPAs ‐Muscle Sequencing

• Based on the initial posture, there is a distinct sequence of muscle activity

– Standing = distal proximal activation

– Sitting = cephalo‐caudal

activation

Woollacott & Shumway‐Cook, 1990Horak & Nashner, 1986,




CPAs ‐ Acquisition• EMG activation during

platform translations causing backward sway

• 27 month old – longer response time and cocontraction

• 5 year old – greater trial variability

• 7 year old ‐ direction specific activation of Tibalis Anterior and Rectus Femoris

Woollacott & Shumway‐Cook, 1990

7 year old Adult

Three Trials


CPA Training• Effect of balance training

on muscle activity used in recovery of stability in children with cerebral palsy: a pilot study.

• Woollacott M, Shumway‐Cook A, Hutchinson S, CiolM, Price R, Kartin D

• Dev Med Child Neurol. 2005 Jul;47(7):455‐61.

• Effect of balance training on recovery of stability in children with cerebral palsy.

• Shumway‐Cook A, Hutchinson S, Kartin D, Price R, Woollacott M

• Dev Med Child Neurol. 2003 Sep;45(9):591‐602.

Postural Control

Children with CP

• Greater and regular sway

• Delayed response to perturbations

• Center of pressure of studies‐

• Trouble fine tuning

• Cephalic caudal recruitment

Anticipatory Postural Adjustments

76

DEVELOPMENT OF APAS


APAs in Sitting• Observed as early as 5 – 6 months prior to reaching

Hadders‐Algra & Brogren, 1996

• Variable responses present at 8 ‐ 9 months during reaching in long sit

Van der Fitts et al, 1999a, 1999b

• APAs reported at 9 months in infants sitting astride a knee a position that requires increased balance

Hofsten/Woollacott, 1989

• CNS can apparently accommodate for different postural tasks (long sit vs. short sit) as early as 9 months



Development of APAs – In Sitting

• Anticipatory postural adjustments emerge as diffuse directionally specific patterns as early as 6 mo during sitting, reaching tasks

Van der Fitts et al, 1999a, 1999

• Variably present at 8 ‐ 9 month during reaching in long sit

Van der Fitts et al, 1999a, 1999

• APAs reported at 9 months in infants sitting astride a knee a position that requires increased balance

Hofsten/Woollacott, 1989

• It appears the CNS can accommodate for different postural tasks (long sit and short sit) as early as 9 months


APAs – In Sitting

• Consistent APAs in sitting by 15 ‐ 18 monthsvan der Fits et al, 1998

• Muscle activity scales with loads when weighted bracelets are placed on the arms of sitting children

van der Fits, Hadders‐Algra et al, , 1998

Refined APAs in sit were correlated with onset of independent walking

APAs in infants with CP were not consistent in sitting by 18 months

van der Fits et al. 1998, 1999

Development of APAs – In Sitting

APAs consistently present in sit by 15 ‐18 months

Muscle activity scaled with load when weighted bracelets were placed in the wrists of the reaching children

APAs similar to adults in spatial features (dorso‐ventral ordering), temporal characteristics (top‐down recruitment), and position dependency

Refined APAs in sit were correlated with onset of independent walking

APAs in infants with CP were not consistent in sitting by 18 months

Van der Fits et al. 1998, 1999


APAs in Standing

Direction specific APAs present as early as 13 months in infants and children with typical motor

development

Cocontraction is present before APAs emergeBarela and Jeka, 1999

Standing infants can scale APAs with loadsWitherington et al, 2002

Anticipatory COP displacements in children prior to standing reach tasks

Riach and Hayes, 1990

Development of APAs – In Standing

• Transition from reactive to anticipatory strategies to maintain standing balance seen in infants who have begun to master independent walking (@13.5 mo olds)

Barela et al. 1999

• APAs begin in stand ‐ 13 – 14 months

• Well developed by 16 – 17 months

Witherington et al 2002


The Development of APAs in Infancy

Drawer Pull Paradigm

Design

• n= 34 infants

• Age: 10‐17 months

• Pulling a cabinet drawer open

• EMG collected from the gastrocnemius and biceps brachii

84

Witherington et al. 2002



APAs – In Standing

• Transition from reactive to anticipatory strategies to maintain standing balance seen in infants who have begun to master independent walking (@13.5 mo olds)

– Cocontraction is present before APAs emergeBarela et al. 1999

• APAs begin in stand ‐ 13 – 14 months

• Well developed by 16 – 17 months

• Scale with magnitude of loadWitherington et al 2002

Development of APAs in Older Children

Unilateral arm raising task in standing (visual stimulus)

• Children 4 – 14 years (n=32)

• Anticipatory changes in COP were present as early as 4 yrs.

• Both AP and lateral COP changes observed

• Younger children had longer reaction times and relied on lateral COP shifts during choice reaction time tasks

Raich and Hayes, 1990


Summary of APA Development• Based on the literature, development of CPAs precedes

development of APAs at each developmental stage

• Theory that internal representation of body in space is necessary for APAs to emerge

Haas et al. 1989

• By age seven typically developing children demonstrate anticipatory mm activity and COP displacements similar to adults for bilateral, unilateral and reciprocal US movements– Direction specificity

– SequencingGirolami et al, 2010


DELAYED DEVELOPMENT

of ANTICIPATORY

POSTURAL CONTROL

Impairments in the sensory

musculoskeletal & neurological

systems

Decreased awareness of

body and environment

Limited motor plans &

decreased variability of movement

Decreased exploration of

the environment

Poor or impaired

perception

Rely on only one sensory

system

Children with APA deficits

CP, Down syndrome, spina bifida, muscular dystrophy, hypotonia, toe walkers, orthopedic conditions, DCD, sensory integration disorder, hearing impairment, autism spectrum disorders, learning disability, etc

Early APA Research

Belenkii, Gurfinkel, Pal’tsev 1967

Biceps FemorisContralateral

Deltoid

Biceps FemorisIpsilateral



Primary Goals of APAs

• Counteract COM displacement associated with the forthcoming movement (Bouisset and Zattara. 1997)

• Counteract the effect of inertial forces on body segments and minimizing changes in body geometry (Pozzo et al. 2001)

• Accelerate the COM in the direction of motion (Stapley et al., 1999, Commisaris et al 2001)

APAs depend on:Direction of Perturbation/Mvt – Sagittal Plane

Erector Spinae

(ES)

Biceps Femoris

(BF)

Shiratori and Latash 1999; Girolami et al 2010

Rectus Abdominis(RA)

Rectus Femoris(RF)

Shoulder flexion Shoulder extension

APAs in children with CP: Shoulder Flexion

93

Time (ms)

TD Hemi DI

Girolami et al 2011

APA depends on:

Direction of Perturbation/mvt (Children)

By age 7, typically developing children are able to generate directionally specific APAs

Girolami et al , 2010

Shoulder flex Shoulder ext

TASK: R shoulder flexion‐L shoulder extension

• Trunk: ~symmetrical APAs between R/L

• LE: asymmetrical APAs between R/L, especially in BF and SOL

96

Shiratori and Aruin 2004

APAs depend on:Direction of Perturbation – Transverse Plane

Unilateral R Shoulder Flexion:

97

0

100

200

1000

500

0

RF

BF

-0.4 -0.2 0.0 0.2 0.4

0

1000

400

200

0

RF

BF

right

left

0

100

200

-0.40 -0.2 0.0 0.2 0.4

1000

500

0

0

500

1000

400

200

0

RF

BF

RF

BF

right

left

TD, 10 yo

Hemi, 16 yo, GMFM88=97%



Difference between TD and CP

• The pattern is present but the APA amplitude is smaller

• APA onset delay observed for some children with CP

98

APAs depend on:

Magnitude of the Perturbation

Arm movement (Horak et al 1984, Lee et al 1987)

Movement speed

Inertial load

Loading (i.e., catching) (Lacquaniti and Maioli, 1990) Mass

Mass/height for catching

Unloading (i.e., dropping a bookbag) Aruin and Latash, 1995)

Mass

TASK: Catching loads of different masses

Dorsal LE/trunk muscle activity scales with mass

Arm muscle activity scales with mass

Shiratori and Latash, 2000

APAs depend on: Magnitude of perturbation--Catching

1.1 kg, 0.4 m

2.2 kg, 0.4 m

APA depends on:Magnitude of predicted perturbation -- Catching

1.1 kg, 0.1 m

1.1 kg, 0.4 m

TASK: Catching 1.1 kg load released from different heights

Dorsal LE/trunk muscle activity scales with height

Arm muscle activity also scales with height

Loading Perturbation: CP

102

0

50

100

150

-0.4 -0.2 0.0 0.2 0.4

1500

1000

500

0

RF

BF

0

50

100

300

200

100

0

RA

ES

0

50

100

400

200

0

RA

ES

0

200

400

-0.4 -0.2 0.0 0.2 0.4

200

100

0

RF

BF

← Hemi, 11.5 yrs old, GMFCS I, GMFM88= 96%

Di, 12 yrs old, GMFCS II, GMFM88= 85%

→

APAs depend on:

Types of perturbation -- Unloading

TASK: release a 2.2 kg held in front of the body with quick shoulder abduction

Decrease in muscle activity in the dorsal muscles (ES and BF) prior to unloading



Unloading Perturbation: CP

104

0

50

100

200

100

RA

ES

0

200

400

-0.4 -0.2 0.0 0.2 0.41000

500

0

RF

BF

0

50

100

400

200

0

RA

ES

0

200

400

-0.4 -0.2 0.0 0.2 0.4

200

100

0

RF

BF

← Hemi, 11.5 yrs old, GMFCS I, GMFM88= 96%

Di, 12 yrs old, GMFCS II, GMFM88= 85%

→

APAs depend on:

Mechanical Stability

TASK: Pull on a handle while supported or unsupported at the shoulder

Unsupported: Prior to self initiated pull (biceps onset), gastroc and hamstrings activates

Supported: APAs decrease in Gastroc

105Cordo and Nashner 1982

APA depends on:

Mechanical Instability

TASK: unilateral shoulder flexion while standing on unstable surface

APAs decrease on unstable condition

(Forrest et al 1998, Slijper and Latash 1999)

Same effect can be observed for load releases on tilt boards

(Gantchev & Dimitrova,1996)

106Slijper and Latash 1999

WHY?

APA depends on:

Perceptual Stability

TASK: Unilateral shoulder flexion while touching a surface with a finger or grasping onto a stable handle

APA decrease with perceptual and mechanical stable conditions

Modified from Slijper and Latash, 2000WHY?

APA depends on:

Fear of Falling (Perceptual Instability)

TASK: Rising onto toes at the edge/away from edge at different heights

Fear of falling decreases APAs and task performance

Adkin & Frank 2002

APA depends on:

Effective body weight-- Immersion in Water

TASK: Pull or push while standing in different levels of water

↓ body weight ↓s APA activity

Dietz & Columbo, 1995

Biceps brachii

Gastroc-nemius



APAs modulate with: Direction of arm movement/ Direction of

perturbation Sagittal Transverse (Frontal and Mix)

Magnitude of the perturbation Speed/inertial load

Loading and unloading perturbation

Stability Mechanically unstable to stable Perceptually unstable or stable

111

Tasks/ Parameters for Designing Exercises

Direction of arm movement/ Direction of perturbation Sagittal Transverse (Frontal and Mix)

Magnitude of the perturbation Speed/inertial load

Loading and unloading perturbation

Effective body weight Water immersion Use of harness Temporary increase in weight

Stability Mechanically unstable to stable Perceptually unstable or stable

112

APAs in Children with CPWhat do we know? Decreased adaptability to task demands

Tomita et al, 2011

Decreased ability to generate mm activity during APAs

Girolami, Shiratori, Aruin, 2011; Tomita et al, 2010

Different postural strategy (mm co-contraction) when generating APAs

Girolami et al, 2011; Tomita et al, 2010

Changes in timing of muscle activity

Girolami et al, 2011Girolami & Shiratori CSM 2013

Hypothesis

APAs decrease in PTs with postural control difficulties because

Incorrect estimation and generation of APAs can increase instability Anson and Latash 1996

increase reliance on CPAs and less on APAs Toussaint et al., 1998

APAs are modulated with limits of stability Manista and Ahmed 2012

PTs with postural deficits likely have smaller limits of stability

114

APA and Learning

Novice versus expert dancers Mouchinino et al, 1992

Learning to generate APAs for novel tasks in healthy adults

Ahmed and Wolpert 2009, Manista and Ahmed 2012

115

Assessment Options



Segmental Assessment of Trunk Control (SATCo)

Butler, Saavedra et al. Pediatr PhysTher. 2010; 22(3): 246–257.

Test form and directions for administration:http://www.bestest.us/files/4413/6358/0759/BESTest.pdf

Mini Bestest: http://www.bestest.us/files/7413/6380/7277/MiniBEST_revised_final_3_8_13.pdf

BESTest (Horak et al 2009)

Model summarizing systems underlying postural control make up the sections of the Balance Evaluation Systems Test (BESTest)

Horak et al. Phys Ther. 2009 May; 89(5): 484–498

POSTURE AND BALANCE• Adkin AL, Frank JS, et al. Fear of falling modifies anticipatory postural control. Exp Brain Res.

2002;143(2): 160‐70.

• Aruin AS, Forrest WR, et al. Anticipatory postural adjustments in conditions of postural instability. Electroencephalogr Clin Neurophysiol. 1998;109(4): 350‐9.

• Aruin A, Shiratori T. Anticipatory postural adjustments while sitting: the effects of different leg supports. Exp Brain Res. 2003:151(1): 46‐53.

• Barela JA, Jeka JJ, et al. The use of somatosensory information during the acquisition of independent upright stance. Infant Motor Behavior. 1999;22(1): 87‐102.

• Belen'kii VE, Gurfinkel VS, et al. Control elements of voluntary movements. Biofizika. 1967;12(1): 135‐41.

• Bouisset S, Zattara M. Biomechanical study of the programming of anticipatory postural adjustments associated with voluntary movement. J Biomech. 1987:20(8): 735‐42.

• Burtner PA, Woollacott MH, Craft GL, Roncesvalles MN. The capacity to adapt to changing balance threats: a comparison of children with cerebral palsy and typically developing children. Dev Neurorehabil. 2007; 10(3):249‐60.

• Donker SF, Ledebt A, Roerdink M, Savelsbergh GJ, Beek PJ. Children with cerebral palsy exhibit greater and more regular postural sway than typically developing children. Exp Brain Res. 2008; 184(3):363‐70.

• Haas G, Diener HC, et al. Development of feedback and feedforward control of upright stance. Dev Med Child Neurol. 1989;31(4): 481‐8.

• Horak F B. Motor control models underlying neurologic rehabilitation of posture in children. Med Sport Sci 1992;36:21‐ 30.

POSTURE AND BALANCE• Horak F. Clinical assessment of balance disorders. Gait & Posture. 1997; 6:76.‐84.

• Horak F, Wrisley DM, et al. The Balance Evaluation Systems Test (BESTest) to differentiate balance deficits. Phys Ther. 2009;89(5): 484‐98.

• Liu W, Zaino C, et al. Anticipatory Postural Adjustments in Children with Cerebral Palsy and Children with Typical Development. Pediatr Phys Ther. 2007;19:188‐195.

• Pozzo TM, Ouamer M, et al. Simulating mechanical consequences of voluntary movement upon whole‐body equilibrium: the arm‐raising paradigm revisited. Biol Cybern. 2001;85(1): 39‐49.

• Van Der Fits IB, Hadders‐Algra M. The development of postural response patterns during reaching in healthy infants. Neurosci Biobehav Rev. 1998;22(4): 521‐6.

• Van der Fits IB, Otten E, et al. The development of postural adjustments during reaching in 6‐ to 18‐month‐old infants. Evidence for two transitions. Exp Brain Res. 1999;126(4): 517‐28.

• Westcott, S. L. and P. A. Burtner. Postural control in children: implications for pediatric practice. Phys Occup Ther Pediatr. 2004;24(1‐2): 5‐55.

• Witherington D, von Hofsten C, Rosander K, Robinette A, Woollacott MW, Bertenthal BL. The Developmental of Anticipatory Postural Adjustments in Infancy. Infancy. 2002;3(4): 495‐517.

• Woollacott M, Shumway‐Cook M, et al. Effect of balance training on muscle activity used in recovery of stability in children with cerebral palsy: a pilot study. Dev Med Child Neurol. 2005;47(7): 455‐61.

• Woollacott, MH, Burtner P, et al. (1998). Development of postural responses during standing in healthy children and children with spastic diplegia. Neurosci Biobehav Rev. 1998; 22(4): 583‐9.

Cerebral Palsy• Brogren, E., M. Hadders‐Algra, et al. Postural control in children with spastic diplegia: muscle

activity during perturbations in sitting. Dev Med Child Neurol. 1996;38(5): 379‐88.

• Brogren, E., M. Hadders‐Algra, et al. Postural control in sitting children with cerebral palsy. Neurosci Biobehav Rev. 1998;22(4): 591‐6.

• Burtner, P. A., M. H. Woollacott, et al. Stance balance control with orthoses in a group of children with spastic cerebral palsy. Dev Med Child Neurol. 1999;41(11): 748‐57.

• Burtner, P. A., M. H. Woollacott, et al. The capacity to adapt to changing balance threats: a comparison of children with cerebral palsy and typically developing children. Dev Neurorehabil. 2007;10(3): 249‐60.

• Carlberg EB, Hadders‐Algra M. Postural dysfunction in children with cerebral palsy: Some implications for therapeutic guidance. Neural Plast. 2005; 12(2‐3):221‐8.

• Liao HF, Mao PJ, Hwang AW. Test‐retest reliability of balance tests in children with cerebral palsy. Dev Med Child Neurol. 2001; 43(3):180‐6.

• Liao HF, Jeng SF, Lai JS, Cheng CK, Hu MH. The relationship between standing and waling function in children with spastic diplegic cerebral palsy. Dev Med Child Neurol. 1997; 39(2):106‐12.

• Palisano R, Rosenbaum P, Walter S, et al. Development and reliability of a system to classify gross motor function in children with cerebral palsy. Dev Med Child Neurol. 1997;39:214–223.

aacpdm ic saturday · saturday, october 19, 2013 ... adaptedfromwoollacott&shumway‐cook,2001...

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