The Influence of Seat Height on Hemiplegic-pattern Propulsion of Manual Wheelchairs

Study Overview
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Brief Summary
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This study evaluates the effect of seat height on hemiplegic-pattern wheelchair propulsion. Each subject will act as their own control and measures will be obtained in a one sixty minute session. Five seat heights relative to the subject's leg length will be measured in a random order to see the effect on forward and backwards wheelchair propulsion.

Detailed Description
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Many people who have suffered a stroke require a wheelchair for mobility. Hemiplegia is a common result of stroke.Many people with hemiplegia propel themselves using their sound-side arms and legs (hemiplegic-pattern propulsion) in manual wheelchairs.Often people using this pattern are prescribed wheelchairs with a reduced seat height to facilitate foot propulsion. Despite the seeming obviousness of the need to lower the seat height for people who use foot propulsion,there is little available evidence to help establish optimal wheelchair seat height. The study objective is to test the hypothesis that there is an optimum wheelchair seat height (expressed as a percentage of the lower leg length) for hemiplegic-pattern wheelchair propulsion. The investigators expect that the optimum seat height will be lower than that usually used for wheelchairs that are hand-propelled. A single-subject design with able-bodied participants will be used to investigate 5 randomized seat heights. The 5 seat heights will be set relative to the subjects leg length at a single 60 minute data collection session All measures will be obtained during one session. The optimal seat height will be chosen based on wheelchair propulsion speed, push frequency and effectiveness over 10m going forward on smooth surface, and 5m going backwards over a soft surface.

Official Title
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The Influence of Seat Height on Hemiplegic-pattern Propulsion of Manual Wheelchairs

Conditions
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Wheelchairs, Hemiplegia

Intervention / Treatment
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* Device: Neutral seat height
* Device: Very low seat height
* Device: Low seat height
* Device: Very high seat height
* Device: High seat height


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: willing to participate is right-hand dominant (to simplify wheelchair and laboratory set-up) has a subjective unshod height of ≤ 183 cm (6'0) is able to be comfortably seated in the manual wheelchair used for the study is 18 years of age or older, is alert and cooperative is competent to provide informed consent is able to communicate in English does not have an unstable medical condition Exclusion Criteria: -

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Single Group Assignment
Interventional Model Description: Single subject - participants will be compared to themselves. STROBE guidelines will be followed.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Seat Height Intervention<br>Randomly assigned 5 wheelchair seat heights ranging from very low (2 below) to very high (2 above) the lower leg length of the participant. | Device: Neutral seat height<br>* Seat height set relative to participant's leg length with neutral set at the measured lower leg length<br>Device: Very low seat height<br>* Seat height set relative to participant's leg length, 2 below the measured lower leg length<br>Device: Low seat height<br>* Seat height set relative to participant's leg length, 1 below the measured lower leg length<br>Device: Very high seat height<br>* Seat height set relative to participant's leg length, 2 above the measured lower leg length<br>Device: High seat height<br>* Seat height set relative to participant's leg length, 1 above the measured lower leg length<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| speed (m/s) | wheelchair propulsion speed over 10 m forward and 5 m backward | same day measure obtained immediately after seat adjustment, approximately 10 minutes | 
| push frequency (cycles per second) | number of foot cycles completed over the 10 m forward and 5 m backward | same day measure obtained immediately after seat adjustment, approximately 10 minutes | 
| Propulsion effectiveness | distance travelled per foot propulsion cycle | same day measure obtained immediately after seat adjustment, approximately 10 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| forward propulsion wheelchair skills test score | fail, pass with difficulty or pass for wheeling forward 10 m | same day measure obtained immediately after seat adjustment, approximately 10 minutes | 
| propulsion difficulty questionnaire | Investigator developed questionnaire asking how difficult it was to perform the propulsion test. The participant will self-report his/her level of difficulty for this skill using a five-point Likert scale (1 =very easy, 2=somewhat easy, 3=neither easy nor difficult, 4= somewhat difficult and 5=very difficult). A single number will be reported. | same day measure obtained immediately after seat adjustment, approximately 10 minutes |