Development of an Ergonomic Manual Wheelchair Pushrim- Phase II

Principal Investigator/s: Ronald M. Boninger, MBA

Co-Investigator/s: Michael L. Boninger, MD; Rory A. Cooper, PhD

2005-2007

People in wheelchairs push on their handrims an average of 2500 times a day and 17,500 times a week as they engage in activities of daily living. The repetitive stress of wheelchair propulsion results in an extraordinarily high incidence of upper extremity pain and injury (as high as 70%) among manual wheelchair users. One alterable source of this problem is the poor design of standard round-tube handrims: they do not provide an ergonomic grip for the hand, they ignore differences in upper-extremity function and they ignore the threat of secondary injury to the upper-extremities. The research proposed here attacks this problem head-on by examining the potential for ergonomic innovations in handrim design to meaningfully reduce the incidence of upper-extremity pain and injury among manual wheelchair users. Phase I research provided initial verification of this potential: After a two week trial use period, subjects indicated highly favorable evaluations of an ergonomic handrim called the Natural-Fit, and analyses of propulsion biomechanics indicated that the Natural-Fit resulted in more efficient wheelchair propulsion than a standard rim.

In Phase II, we develop and test the effectiveness of ergonomic handrim designs that addresses differences in upper-extremity function (paraplegia vs. tetraplegia) and differences between men, women and children. We set forth four goals: 1) Create size options to better customize the fit to the hand for additional target populations, particularly women and children. 2) Test coating alternatives to optimize the effectiveness and durability of high-friction propulsion surfaces. 3) Design and test a handrim tailored to the propulsion style and hand function of people with tetraplegia. 4) Conduct a multi-site randomized single blinded control study that incorporates a 4-month trial-use period to systematically examine the long-term consequences of using the ergonomic handrims developed in this research.