Evaluation of two wheelchair hand rim models: contact pressure distribution in straight line and curve trajectories.

Manual wheelchairs are essential for people with disabilities or limited mobility. However, manual propulsion causes biomechanical loads, including contact pressures on the palms of the hands. The hand rim design has received little attention over time, remaining almost unchanged since its creation. This study investigated how two different designs of such devices - one standard and another with a contoured design - influence the contact pressure on the surface of the hands. The procedures included a figure-of-eight shape propulsion task on a regular floor, using both models on a wheelchair. A pressure-mapping system coupled with a pair of fabric gloves recorded the data. The results show that the contoured hand rim provides lower pressure in most of the analysed regions. Considering that manual propulsion is performed during a considerable part of the day as a routine activity, improving the hand rim interface may benefit the user's comfort and safety during wheelchair use. Practitioner summary: The design of the hand rim used in wheelchair propulsion influences the contact pressure on the hands. Conventional round tube rims tend to concentrate high levels of pressure on the distal phalanges and metacarpal regions. A contoured design generally provides better stability and promotes the distribution of pressure. Abbreviations: AT: assistive technology; kPa: kilopascal.