THE DESIGN OF SCHOOL FURNITURE FOR PRIMARY SCHOOL CHILDREN

Simon Dennehy

Department of Industrial DesignNational College of Art and Design

100 Thomas StDublin, Ireland

Abstract

This paper outlines the research and design process involved in the development of Perch - A school chair and desk for primary school children, and documents the implementation of a new and innovative solution. School children experience a surprisingly high level of discomfort, pain, injury and musculoskeletal disorder, due to the prolonged use of unsuitable seating and desks. Statistics show that half of all children... have back problems at some time and that in 8% of cases it is serious enough to affect their attendance at school (ELLIOTT, J. 2006). This is not unique to the Irish education system; numerous studies have shown that this is a global problem. Primary school children require carefully designed furniture in the classroom, where they regularly maintain static postures for long periods of time. More importantly, primary schools prepare children for a sedentary way of life. The project centres on the investigation of ergonomics and usability, the exploration of this research in a series of user tests and the creative implementation of the results in a new design. The solution proposed incorporates a new, patented, flexible seat pan, with a unique height adjustment feature and adjustable desk with sloped worksurface. The improved posture and the practical resolution of storage facilities offer students and teachers improved flexibility in the classroom and overall enhanced modern learning environments.

1.0 Introduction

Ergonomic furniture ultimately ensures increased performance and productivity. (Breithecker, Dr. B. 2006). Active sitting has been a focal point for leading producers, ergonomists and designers for many years. The ability of end users to change posture and position throughout the course of the day, attain and maintain open posture, while relieving unnecessary load from the mid-section and back, helps to prevent long term damage associated with traditional right angles sitting. With most companies focused on reclined positions to achieve open posture, the concept of forward and upright sitting has been overlooked for mainstream task seating. Within the niches, there are companies selling furniture to encourage high sitting, pelvic tilt, and open postures, but these products remain well outside the mainstream, despite their advantages. The benefits of open posture and active sitting are now recognised for being far healthier than the right-angles approach. The project illustrates how significantly higher sitting, where the subject sits upright with open posture, toward an elevated and sloped work desk, can positively affect the physiological and psychological state of the school child.

It is irresponsible to design school furniture for students, without gaining an understanding for their requirements. Primary education aims to achieve basic literacy and numeracy for all. In the process of learning to read and write, students focus intently on material immediately in front of them, on a desk, and traditionally from a seated position. It was apparent, from early in the study, that the current accepted standards for school furniture are fundamentally flawed. Rear sloping or horizontal seat pans with horizontal worksurfaces, where right-angles sitting is encouraged, simply forced students into unimaginable postures, where discomfort and pain are experienced daily. The Perch design provides a significantly elevated seat and work surface height. Students are encouraged to sit with an open posture, where the angle between torso and thighs far exceed ninety degrees. The findings suggest that chair and desk designs must be considered as items of equal importance.

A User First Design approach guided the literature review, design, testing and prototype phases of this project. The final designs remain true to the needs and requirements of the student during class time.

2.0 Design Implementation

2.1 Seat Design

The Author's theory that a reason for the failure of niche products, such as kneel, forward tilt, or saddle chairs, is due to remarkable and unique aesthetic. This view is shared by many leading task furniture producers. The aesthetic has been a driving force in chair design for decades. The chair has become an iconic representation of western culture and is embedded into society. Appearance and proportion play important roles when buying furniture pieces. Though hugely diverse in terms of material and colour choices, for the most part, chairs conform to certain physical and proportional criteria to look right. Products such as kneel and saddle seats undoubtedly, fall outside of this traditional aesthetic.

The aim of Perch is to increase the range of postures available to the user, encourage more movement and activity throughout the entire body, while respecting the traditional seating aesthetic when the chair is not in use.

A detailed study of specialist seating was conducted and their benefits and flaws were noted. When saddle seats are used at low sitting heights, the body area in contact with the seat pan is significantly reduced, and a large increase of pressure on the ischial tuberosities results. Finding ones Ideal siting height

Figure 1: Perch - School Furniture

becomes a must on saddle seats. The exaggerated pommel at the front of the chair can be off putting to certain users, and it can be difficult to mount and dismount as a result.

Kneel chairs hold the users' legs in position for long times. It is

a worry that, when sitting in a group away from a desk, the student is susceptible to helpless and dangerous falls forward, because of an inability to quickly stabilise (a result from horseplay). Forward tilt seats place an increased load on the users legs and the tendencies are for the chair to slide backwards, especially on floors with a low coefficient of friction. These chairs also, only work for the student when adjusted to the optimum height and are quite unusable at low levels.

It is clear from literature reviews and observation in schools that students will attain postures to suit the task work, rather than comfort. Teaching them the values of sitting appropriately is very important, but restricting adjustability simply restricts the student. A seat to accommodate the student comfortably, at all sitting heights and during task work, became the aim.

The Perch seat pan incorporates a flexible surface (wing) at each front corner (fig 2). These wings remain in contact with the users' legs (back of femur), regardless of their seated height, without restricting circulation to the legs caused by hard edges. In elevated positions, the Wings organically adjust and flex to accommodate any femur position, asymmetrical or not.

During testing, it was common to see students frequently

moving both legs up and down, in a pedalling motion, as a result of seat flexion. When sitting high where the femur to spine angle approaches 135, the pelvis is rotated forward, and a position of lordosis is attained. This contributes to a straighter upper back and reduced stress on neck muscles. Hip abduction, while sitting on the flexible seat helps to stabilize the pelvis in an upright position. Balance is improved by the rigid front pommel, which stabilises the location of the subjects' buttocks and sit bones. In an upright, open posture, a subject will make use of the major and strongest muscle groups of the body. Stomach and back muscles are in balance and the leg muscle groups get utilised. In a reclined position, this is less the case.

There is no one good position for sitting all day long, and

regular movement of the upper and lower body is to be encouraged to stimulate muscle growth, blood flow and circulation. During right-angles sitting, observation and analysis has shown, how underused the lower body, from the chest to the toes, become during task work. In almost all cases, the lower body practically ceases to work. This lack of movement will contribute to muscle atrophy and, at such an early age, will prevent the proper development of muscle groups around the stomach, back and legs of the subject. The most direct effect of sitting idle is that the work performed by the large skeletal muscles in the legs, back, and trunk required for upright movement comes to a halt. (HAMILTON, M.T, et al 2007)

With the Perch solution, in all cases, students were seen to considerably increase movement throughout their entire bodies during task work, without any perceived loss of concentration

Figure 2: Flexible "Wing" sections

Figure 3: Height adjustment feature

or distraction towards course work. To the contrary, reports indicate an overwhelming improvement in comfort and satisfaction. The seat uses hundreds of ventilated slots throughout. On saddle chairs, heat build up around the pubic region is an area for concern, especially when long term sitting occurs. These vents allow approximately 30 percent of material to be removed, increasing airflow and cooling, while reducing weight and unit cost.

On the Perch chair, a user can sit at any height, while maintaining the same level of leg support and freedom of movement. The ischial tuberosities remain in contact with the rigid rear section of the chair. When sitting low, or when not in use, the front pommel practically disappears, as the wings return back up into a neutral and horizontal resting position. Once the student dismounts the chair, the aesthetic is similar to traditional seat pan styles.

The chair provides a leg rest, where the student can engage one or two feet at a time, then alternate back onto the floor, as required. The chair also includes a unique and safe height adjustment. It is not possible to disengage from a set height while the user is sitting. The lowering of the seat can only be accomplished when the subject dismounts the chair and pivots the seat arm, which in turn, disengages the lock and allows readjustment (fig 3).

2.2 Desk Design

The height adjustable desk improves accessibility and functionality for students as they learn to read and write. Incorporated is a flat front ledge, where students rest their arms or elbows to relieve load to their mid-section. Investigating poor posture among school children revealed that Optimal Visual Distance (OVD) dictates the head position of the student. In all cases, students brought their heads approximately 300mm from their work, when they were required to read or write. They do so at the expense of comfort and continue working in this position for long periods. (Fig 4)

Most school seats are slightly reclined and work surfaces are

generally horizontal. The user is required to form an excessive kyphotic posture in order to achieve their OVD. By sloping the work toward the student at 25, the work is accessible (Fig 5).

By raising the work surface height, postural kyphosis is reduced as the student does not need to bend over as much. Noted was the small desk area actually utilised during task work, again due to the need to keep work within OVD. Desks are traditionally 600mm deep, but students only ever used about 400mm, with the remaining surface being used for storing books and accessories. The Perch desk shortens the writing surface and incorporates a storage trough at the rear. When sitting higher, with hip abduction, the reach of a student is increased, which allows the students access to items at the rear of the desk.

Also incorporated is a reading ledge (Figure 5: A-B), which potentially extends the footprint of the desk, for when students are copying from a book. Its inclusion takes inspiration from students' ability to read clearly from far distances, (e.g. blackboards). It seems that, only during intensive creation based task work, or intensive reading, is the work required to be close to the students.

The desk offers an accessories tray at the rear of the desk and is replaceable with multiple solutions, such as a removable and

Figure 4: Poor posture because of OVD requirement

Figure 5: Desk Profile

stackable system for Arts and Crafts, Lego trays etc. The desk is fully height adjustable, allowing all students to be accommodated. Finally, a soft and tactile, rubberised surface was applied to the work area of the desk. This provides an easy to clean, warm and haptic surface that grips work and prevents slippage.

2.3 Evaluation of Designs

Evaluation was carried out using two digital video recorders and one high quality digital SLR camera. The video cameras were positioned with one directly in front of the students, looking at their heads, torso and arm movements and the second at right angles to the furniture. This monitored their side profile during work. The SLR camera was used by the researcher to take photographs at various angles and positions throughout the trials. Initially, the furniture was set up in a common area within the school, away from the classroom. An introductory trial was crucial, so an understanding of the students' initial reaction to the rigs could be assessed. This meant less disruption, once the furniture was brought into the classroom. Students were made aware of the conditions, and shown the various adjustment features available to them.

Pairs of students were selected by teachers. Tall and small were paired together. Groups aging between 8 - 12 years were tested during the final trials, though during initial concept testing, the range was far broader and included students from age 6 12 years.

Students were assigned written course work. The desk was initially dropped to a low setting (approx 600m high) and the students always maintained full control over their seating height. Incremental adjustments were made intermittently to the desk height and slope. By the end of the experiment, all students were working at heights of in excess of 750mm (the height of elbow ledge at front of desk). The taller students chose higher work surface heights of almost 800mm. It was interesting to note how high the students preferred to sit. By the end of the experiment, even the third class (9 years) students were sitting above 420mm high (Fig 6). It should be

made clear, that the author, never communicated a need to sit higher. This was totally voluntary on behalf of all students. They also requested the desk heights to be raised and reported being most comfortable when working at the high ranges. Once ten students (five pairs) had trialled the furniture, the experiment was set up in a classroom.

The same students would use the furniture again in this setting. The rig was moved toward the rear and centre of the room, with desk set at 750 mm high which had previously been determined. The students were told that they could adjust this height as required. When class time commenced, the author left the room, and set the two video recorders to capture the side profile of each student. The teacher was told to perform as usual and to allow the subjects to alter their furniture as required. Every 40-60 minutes (depending on teachers preference), the students swapped with another pair. Though these test periods were short term the longest trial being just over 1 hour it clearly highlighted important issues and guided each progressive development phase. In particular, the flexible seat pan proved to be exceptionally comfortable and practical for both task work and relaxing periods. The chair could be used by any student at any selected height and without discomfort. In all tests and trials, the students, chose to adjust their furniture to eventually work at higher levels, with more open and active postures. The higher, the better for desk and seat heights. In group work, where they sat around without a desk, a slightly lower sitting position was maintained and the students sat in a more reclined position. Allowing for variation in sitting postures is important.

There were two schools selected for user trials and the results from both schools showed very similar results. The resulting designs of Perch were a direct result of testing, evaluating and collaborating with students, teachers and parents.

3.0 Conclusion

Dr. Waseem Amir Bashir, a clinical fellow in radiology at the University of Alberta Hospital, concluded that humans were not created to sit down for long hours, but somehow modern life requires the vast majority of the global population to work in a seated position ... This made our search for the optimal sitting position all the more important, (WARD, D. 2006). Their focused study pinpointed the open seated posture of 135 as least damaging. Using positional MRI scans, they monitored the intradiscinal pressure and strains on the spine during sitting in various postures. These findings corroborate with research from Mandal, and many more outliers who have suggested utilising open posture for some time. From the work carried out during and after this M.A project, and from interviewing leading researchers, such as Eileen Vollowitz, and representatives of leading contract furniture producers, it is clear that focus on active sitting in a reclined position has been a central focal point, within mainstream task furniture, for some years now. This position allows the subject to relax, rest and sustain a relatively unstressful working position when seated. In a reclined posture, however, there is an absence of full body movement and meaningful engagement throughout the skeletal muscles. Findings from Marc Hamilton (et al), suggest that inactivity, as well as poor posture play key roles in seating related illnesses. ...this global trend is likely to continue, given the increasing availability and popularity of personal computers, TV, automation of chores at home, transportation trends, and further inventions in the future. The most direct effect of sitting idle is that the work performed by

the large skeletal muscles in the legs, back, and trunk required for upright movement comes to a halt. (HAMILTON, M.T, et al 2007)

Activity throughout the course of the day is vital for a healthy lifestyle. Accommodating children in a reclined position is not feasible due to the type of course work within primary education. Even if it was however, it seems almost pathological to allow such a passive and inactive way of working to creep in. Perch concentrates on sitting high, upright and with open posture. Moreover, it promotes active sitting and continuous movement throughout the body, and promotes activity throughout the major muscle groups.

Because of the ability of young students to repair damage to their intervertebral discs, for the most part, poorly designed furniture tends to be overlooked. Students are training themselves to sit very inappropriately. As they mature and lose their repair mechanisms, they become immune to these postures. The dire concern for the future may rest with growing numbers unaware of the potential insidious dangers of sitting too much (Daily mail, 2007). The project is now progressing toward more advanced user trials.

Proving the theories relating higher sitting and working with the Perch flexible seat pan and contoured desk profile requires long term evaluation with a large sample audience. This is now being undertaken as part of a PhD study with the National College of Art and Design and GradCAM (Dublin, Ireland). This work will be peer reviewed and published.

Figure 6: Ergonomic illustration and Testing

Bibliography

BackCare, The Charity for Healthier Backs . 2008. [online]. [Accessed 17th January 2008]. Available from World Wide Web:

Breithecker, Dr.B. 2006. Beware of the Sitting Trap in Learning and Schooling, Ergo-dynamic concepts are decisive. [online]. [Accessed 17th January 2008]. Available from World Wide Web:

CRANZ, G, 1998. The Chair, Rethinking Culture, body, and Design. New York: W.W. Norton & Company, Inc.

Daily mail. 2007. [online]. [Accessed 17th January 2008]. Available from World Wide Web:

Diffrient, N. 1990, More Than Meets the Eye, The Design of Performance Furniture for the Office. The Design Arts Program of the National Endowment for the Arts, USA.

ELLIOTT, J. 2006. School books - a pain in the back [online]. [Accessed Thursday, 17th January 2008]. Available from World Wide Web :

Forget sitting upright to prevent back problems: radiologists, CBC News, November 27, 2006, [online]. [Accessed 17th January 2008]. Available from World Wide Web: http://www.cbc.ca/health/story/2006/11/27/sit-posture.html

HAMILTON, M.T, - HAMILTON D.G. - AND ZDERIC, T.W. 2007. Role of Low Energy Expenditure and Sitting in Obesity, Metabolic

Syndrome, Type 2 Diabetes, and Cardiovascular Disease. Diabetes. Volume 56, page 2665.

MANDAL, A.C. (3rd ed). 1985. The Seated Man, Homo Sedens. Denmark: Dafnia Publications.

Murphy, S. 2008. Interview with the researcher on January 15th. Belfast. [Cassette recording in possession of author].

O Conchubhair, G, 2004. PhD research The principle of 'Equatilt' - the design and development of seating for orchestral musicians, The National College of Art and Design, Dublin.

Simon Dennehy