One-hand user wheelchair development

The standard manual wheelchair is an effective, but inefficient means of transport particularly for people who have experienced a stroke and have a resultant hemiplegia. Having summarised the literature regarding wheelchair provision for hemiplegic subjects, the research team identified a lack of suitable provision. In response to this issue, and in conjunction with a stroke rehabilitation team, stroke patients and an engineer, the team designed a novel ergonomic self-propelled steering (ESP1) mechanism kit which could be attached to a standard manual wheelchair. The novel steering mechanism kits enables the user to steer with the footplate, and propel the wheelchair with only one pushrim. In addition, the kits can be attached to either side for use by either the right or left handed users and enables the wheelchair to be steered independently from the propulsion.

The ESP incorporates two innovations: a gear differential built into one drive wheel and an engageable/disengageable foot steering involving one front castor. The axle is not affected and can still be removed in order that the wheelchair can be collapsed for storage. These devices are fitted to the wheelchair on the users’ functional side and are operated independently by the individuals with a cerebrovascular accident (CVA) who use a wheelchair. The differential enables a single pushrim to drive both rear wheels equally resulting in the wheelchair moving in a straight line with steering that can be employed as required.

This project was funded with a Department of Health HTD grant.

Project aims

The aim of this pilot study using hemiplegic subjects was to measure energy expenditure, hand position and ride comfort, in a standard dual handrim Sunrise Breezy wheelchair compared to one modified with a novel ergonomic selfpropelled steering (ESP) mechanism kit. A previous study by Mandy et al. (Disabil Rehabil Assist Technol 2007;2:255–260) reported that the attachment of the ESP kit to a standard Sunrise Breezy wheelchair provided a more ergonomically efficient mechanism for wheelchair steering and propulsion for non-disabled individuals.

Thirteen hemiplegic stroke users participated in a repeated measures trial by driving two manual wheelchairs – a standard manual dual handrim wheelchair and one fitted with the ESP steering conversion kit. Wheelchairs were randomly assigned, to participants who drove each wheelchair around a designated circuit. Oxygen consumption, carbon dioxide and heart rate were measured as indicators of ergonomic efficiency using a Cosmed analyser. Comfort for each wheelchair was measured using a validated questionnaire.

Project impact

Oxygen consumption (O2mls/min) and exhaled carbon dioxide (CO2mls/min) were significantly lower in the modified wheelchair. Time taken to complete the course was significantly faster in the ESP (p50.001). There was no significant difference in heart rate readings between the wheelchairs. All comfort ratings were reported to be significantly greater in the ESP.

The results from the pilot study of hemiplegic users suggest that the ESP is a viable kit that has the potential to be a useful attachment to the standard dual handrim Sunrise Breezy wheelchair. The results suggest that the kits make propulsion of the wheelchair easier, and more comfortable to drive. The kits also potentially afford individuals with a CVA, who use a wheelchair, a satisfactory alternative to current wheelchair provision. The engineering of the prototype was robust and resulted in adequate wheelchair performance under trial conditions. There is a clear justification for the ESP Wheelchair to be tested in users’ homes.

Project team

Anne Mandy

Samuel Lesley

Outputs

Final paper (PDF)

Partners