Custom molded seating and temperature regulation by hilen


									Custom moulded seating and temperature regulation Kos C, Chapple P Abstract Some clients require a highly contoured seating system to support body structures where muscle weakness, fixed deformities or a high level of tone exists. Contoured systems can promote improved postural alignment, pressure distribution and functional abilities; however this type of seating can result in increased heat production, as it sits closer to the person’s skin over a larger surface area. The impact of increased heat, moisture and sweat upon the individual’s comfort, health, quality of life and function, and the lifespan and integrity of the seating systems is considerable, however limited evidence exists for interventions that address this. The purpose of this paper is two-fold. Firstly, it will outline the process undertaken by a seating team to trial and investigate the affects of attaching a breathable product (Supracor) to contoured seating to aide temperature regulation. This will include a demonstration of the practical technologies employed and a summary of trial results and outcomes. Secondly, it will illustrate the approach taken to research appropriate literature and collect and analyse data from the trials, using the Goal Attainment Scale (GAS). This paper will be of relevance to those with an interest in custom moulded seating, temperature regulation and evidence based practice.

1. Custom moulded seating systems Many clients with physical disabilities are prescribed custom moulded seating systems for their wheelchair. This is usually due to the inability to comfortably, safely and functionally seat the individual in a commercially available system (Hollettt and Hundertmark 1985). The documented evidence for the clinical benefits of custom contoured seating is limited, however some of the positive features found in the literature include:  Increased head control (Lemaire E. D, Upton D, Paialunga J, Martel G, Boucher J, 1996).  Increased sitting time – attributed to the reduced concentration and redistribution of sitting pressures over the seated area (Lemaire E at al 1996).  Improved reaching / grasping and functional capabilities, allowing increased access to technology. (Sharman A and Ponton T 1990).  Easier social interaction, by promoting an upright, midline posture to improve an individual‟s visual field (Lemaire E at al 1996, Sharman A and Ponton T 1990).  Improved sitting posture – by providing full body contact support, promoting symmetrical posture (Schuch et al 2000).  Improved correction and accommodation of complex postural deformities such as spinal deviations – due to ability to customise to a person‟s individual shape (Lemaire E at al 1996).  Ability to modify shape to suit individual sensitivities and reactions (Schuch J. Z, Donaldson A and Baumgartner P, 2000).  Provision of proximal stability for people with athetosis to discourage the development of compensatory strategies (Schuch et al 2000).

2. Purpose TASC Seating service receives many referrals from clients requiring custom contoured seating systems to support their posture. Clients report many of the positive features referred to in the literature, however one of the detrimental effects when compared to a component system is an increase in heat production and resultant sweating and moisture build up. This has been repeatedly reported by care staff and clients and had previously gone unresolved. The intention of this paper is to present a single case study outlining the process the seating team undertook to address the issue of temperature control in customised seating, utilising an evidence based approach. Discussion is based on the team‟s clinical experience and review of current literature and technology.

3. Participants 2 Seating Consultants and a Technician from TASC collaborated with the client (Mary*), her parents and local Occupational Therapist. Mary was 24 years old, diagnosed with Cerebral Palsy (Spastic Quadriplegia) and severe Intellectual Disability. She was non-verbal and resided at home with support from family and attended a day program 3 times/week. She was dependent for all activities of daily living. Mary‟s postural needs were significant and she had been recently supplied with a contoured seating system. Upon follow-up it was reported that the system was beneficial in meeting Mary‟s postural needs, however she was experiencing difficulties as it was “too hot” for her. Some of the reported indicators of excess heat production included:


Not client’s real name – synonym to be used throughout paper

   

excessive sweating behaviour surrounding communication of discomfort skin feeling hot to touch „heat rash‟ appearing on skin

It appeared that the problems could be directly attributed to the new seating system. Although Mary‟s posture was improved in the seating, it was reported that she was spending large periods of time out of the system (on the family lounge) due to these issues. This caused postural, functional and social causes for concern and it was agreed that a solution needed to be found to rectify these issues.

4. Process: 4.1 Literature Search: A literature search was conducted to identify the most appropriate clinical intervention and best practice to rectify the issues. The PICO model of literature search was followed to refine the question and guide the search strategy. PROBLEM / CLIENT GROUP INTERVENTION COMPARISON OUTCOME The problem or search questions posed were: “What is the evidence for the incidence of elevated body temperature caused by the use of a custom contoured seating system?”

“What evidence exists for techniques to reduce body temperature associated with the use of a custom contoured seating system?” The OUTCOME terms focused on the following      Temperature reduction Sweating Body temperature Thermoregulation Body temperature regulation

The search did not return any literature directly addressing the question posed. One article was identified which compared the effect of various cushion materials on skin temperature. Seymour R and Lacefield W (1985). Wheelchair Cushion Effect on Pressure and Skin Temperature. Archives of Physical and Medical Rehabilitation, 66: 103-108. The article compared the effect of cushion material on patients with spinal chord injury versus an able bodied person and concluded foam based cushions create a higher mean temperature compared with gel, water or air cushions.


Product and measurement tool selection

Without any reliable clinical information from the search it was decided to investigate implementation of a new practice to the seating team. Discussion with peers and product investigation suggested the trial of the material „supracor‟. Anecdotally supracor was reported to be an effective means of addressing temperature regulation in seating systems, however there was little evidence available regarding specific outcomes or

recommended applications for client populations. In order to obtain data from the trial the Goal Attainment Scale (GAS) was used as an outcome measure.

4.2.1 Supracor: Properties and indications for use Thermostatic Supracor is described as breathable honeycomb sheets that can be used over any seating or positioning surface. Supracor is marketed as being:   Resilient yet lightweight A unique composition of cells that assist with pressure management and ventilation   Not affected by bodily fluids Odour resistant

Supracor has a range of medical products including:      Pressure relief and positioning cushions (Stimulite) Honeycomb pillow Lumbar support Mattress overlays Bassinett mattresses

It is advised that sheets are washed after a period of use.

4.2.2 The Goal Attainment Scale (GAS) The GAS is an “individualized, criterion referenced measure of change using goals” (Novak, 2004 p.1). It was developed to relate interventions to clearly stated goals and then demonstrate the client‟s progress towards them (Kiresk & Sherman 1968 in Novak, 2004)

The procedure for implementing a GAS includes: 1. Identify client goals 2. Weight the importance of each goal 3. Predict a range of 5 possible outcomes and assign numeric values (ranging from –2 to +2) to each according to expected results from intervention. A weighting of 0 reflects the expected outcome and a rating of –2 represents the baseline performance (refer to table below). Goal: Predicted Level of Attainment -2 (much less than expected) -1 (less than expected) 0 (expected at level end of of Goal

performance treatment)

+1 (better than expected) +2 (much better than expected)

4. Establish conditions for implementation of GAS (include time frames, environment and assigned reporter/s) 5. Conduct intervention 6. Score results using observed outcomes and GAS at follow-up 7. Interpret scores into a GAS t-score (using formula or conversion table). This reflects the overall change resultant from the intervention (Bowman, Cook, McCluskey & Mogensen, 2005).


Technical planning

The TASC Seating Consultants and Technicians met to identify the issues inherent in trialing the new technology. Specific attention was paid to:     Ensuring overall width and fit of the backrest was not altered significantly Ensuring Mary‟s posture was not compromised Practical methods of allowing family to remove and wash the supracor Technical considerations to promote optimal air flow and circulation



A series of appointments were conducted with the client and local team, consisting of: 4.4.1 Fitting 1  Posture

Mary‟s posture was assessed and documented for comparison (to ensure that the introduction of supracor did not result in any other changes that could also influence temperature regulation). 

Goal setting and establishing the GAS Mary‟s problems with temperature regulation were discussed in detail. Specific

attention was paid to extracting information about: what the problems were how the team knew that these problems existed for Mary what the functional ramifications of the problems were

This formulated realistic and easily understood goals, which could be accurately monitored by the family.

Three goals were identified in relation to temperature control and transferred onto respective goal attainment scales (see appendix 1 for details). Insertion of supracor

The „comfort layer‟ of foam, approximately 1” thick was removed from the original backrest and replaced with a soft, thin layer of foam approximately 5mm thick. The soft layer of foam was used to protect the underlying layers of foam and reduce the chance of ridges forming from where the original backrest had been fabricated. This formed a smooth base for the addition of the supracor and the thickness of the foam was predicted to be negligible (especially due to compression factors). A layer of supracor approximately 1” thick was placed on top of the layer of soft foam and Mary was transferred into the system. It was noted that the team‟s ability to transfer and position Mary had not been altered by the supracor. A postural assessment was conducted and Mary‟s posture did not show any significant changes when compared to previous assessment results. The system was left at TASC for completion. The backrest (consisting of dense layer and thin soft layer of foam) was upholstered using datex and vinyl. A mesh microfibre pocket was fabricated to encase the supracor and stimulate air flow and circulation. The top of the mesh pocket was fitted with Velcro, allowing removal of the supracor for washing. The mesh pocket (with supracor insitu) was fitted with elastic to allow it to be easily attached to the rest of the backrest.

4.4.2 Fitting 2: The local team returned to collect the completed seating for a trial period of approximately 3 weeks. Postural assessment and consideration for transferring and

positioning was again conducted and found to be consistent, despite introduction of supracor and upholstery. When Mary was seated it was noted that the supracor adopted the contoured shape of the backrest well. The GAS was reviewed (particularly with Mary‟s mother who was to provide feedback during and after the trial period). 4.4.3 Home Visit The team met at Mary‟s home at the conclusion of the trial and gathered information through interview and review of the GAS results about how the supracor had addressed Mary‟s identified goals. 5. Results

Mary‟s primary carer reported a high level of improvement in relation to all the indicators of increased heat production. The outcomes measured for all goals were above the 0 level expected. The level observed for each goal was +1, +1 and +2 for goals 1, 2 and 3 respectively. This indicates that the client no longer required frequent clothing changes due to build up of moisture, was no longer communicating any level of discomfort and there was no appearance of redness heat or blistering when the client was removed from the backrest. When this outcome was converted using Cardillo‟s conversion table for three scored scales, the intervention achieved a GAS t-score of 68.26. For a score above 50 (with maximum score possible of 77.38), this indicates that the results achieved were well above what was expected. Additional feedback revealed that Mary was able to spend the majority of the day in her seating and increasingly accessed the outdoor environment.



The primary therapist was contacted approximately 6-weeks post home visit appointment. The therapist reported that the positive results remained and that Mary could consequently be discharged from the seating service. 7. Discussion

Following the success of the intervention it is expected that the service will repeat product trials for clients with similar needs in the future. Temperature regulation is now discussed in detail at initial assessment to determine if it is likely to be an issue for clients. The use of supracor is still in the experimental stage and would need to be carefully prescribed by the seating team for each individual case. Due to the limited scope of the trial methods this intervention could not be considered as a best practice option for this or any other client group. However, from the results achieved from this single client case and applying the similarities to other clients it shows great promise as a possible intervention and solution to some of the temperature regulation problems experienced. The therapists found utilising the GAS beneficial in assisting the client and their family to identify meaningful and realistic goals that guided intervention and promoted increased objectivity in evaluation. The GAS has been identified as a useful measurement tool for developing seating goals and evaluating outcomes and the team are identifying strategies to incorporate it‟s use in everyday practice to strengthen their evidence base and client satisfaction. Other tools that the therapists found useful included conducting 6-week follow-up to the local team and repeated use of postural assessments to monitor if any other changes were brought about by the intervention.



Supracor was found to alleviate the issues related to temperature regulation for a client with custom moulded seating. The GAS was beneficial in identifying realistic and specific client-focussed goals and evaluating the success of the intervention. Further trials of temperature regulating products using the GAS or a similar outcome measure are suggested to enhance the evidence base for this commonly reported issue for clients requiring custom moulded seating.


Bowman, J., Cook, C., McCluskey, A., Mogensen, L. (2005). Increasing allied health clinicians‟ use of outcome measures. Workshop presented at The Spastic Centre continuing education day, Sydney, New South Wales. Huntermark, L. H. (1985). Evaluating the adult with cerebral palsy for specialised adaptive seating. Physical Therapy, 65(2); 209 – 212. Katz, K., Liebertal, M., and Erken, E. H. (1988). Seat insert for cerebral palsied children with total body involvement. Developmental Medicine and Child Neurology, 30; 222 – 226. Lemaire, E. D., Upton, D., Paialunga, J., Martel, G., Boucher, J. (1996). Clinical analysis of a CAD/CAM system for custom seating: A comparison with hand-sculpting methods. Journal of Rehabilitation Research and Development, 33(3); 311 – 320. Novak, I. (2004). Goal attainment scaling. Paper presented at The Spastic Centre rural therapy conference, Pokolbin, New South Wales. Schuch, J. Z., Donaldson, A., & Baumgartner, P. (2000). Carving a niche. Rehabilitation management: The interdisciplinary journal of rehabilitation, 13(6); 84, 86, 88. Seymour, R. J., & Lacefield, W. E. (1985). Wheelchair cushion effect on pressure and skin temperature. Archives of Physical Medicine and Rehabilitation, 66; 103 – 108. Sharman, A., & Ponton, T. (1990). The social, functional and physiological benefits of intimately-contoured customised seating: The matrix body support system.

Physiotherapy, 76(3); 187 – 192.

Appendix 1 Goal 1: When at home for the day, Mary will sweat less in the chair, requiring fewer changes of clothes per day. Predicted Level of Goal Attainment -2 (much less than required 3 changes of √ expected) clothes because ‘wet’ with sweat -1 (less than required 2 changes of clothes because ‘wet’ with sweat 0 (expected level of required 1 change of performance at end clothes because ‘wet’ of treatment) +1 (better with sweat than required 0 changes of clothes because ‘wet’ with sweat +2 (much better able to wear warmer clothes and not require any changes of clothing due to being ‘wet’ with sweat √ Baseline Postintervention



than expected)

Conditions:  To be completed on days when Mary is home all day (i.e. not attending day placement)  To be completed by primary carer (mother)

Goal 2: Mary will communicate less discomfort (screaming, increased tone and biting hands) when arriving home at the end of the day. Predicted Level of Goal Attainment -2 (much less than Mary expected) -1 (less communicated √ Baseline Postintervention

extreme discomfort than Mary communicated a lot of discomfort


0 (expected level of Mary communicated a performance at end little bit of discomfort of treatment) +1 (better than Mary communicated no discomfort better Mary communicated √

expected) +2 (much

than expected)

that she was very happy

Conditions:  To be completed on days when Mary attends her day placement, when she arrives home on the bus  To be completed by Mary‟s primary communication partner (her mother)

Goal 3: Mary’s skin on her back will appear less irritated (red, hot, blistered) when checked during personal care. Predicted Level of Goal Attainment -2 (much less than Back was hot, red and √ expected) had many blisters Baseline Postintervention

(more than 3) -1 (less than Back was hot, red and had some blisters


0 (expected level of Back was hot and red performance at end (no blistering) of treatment) +1 (better than Back was hot (no


redness or blistering) √

+2 (much better than No heat, redness nor expected) blistering

Conditions:  To be completed on days when Mary is home all day (i.e. not attending day placement).  To be completed by primary carer (mother) during episodes of personal care in the afternoon

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