Biomechanics and Motion Analysis

Kinematics of the Upper Extremity in Wheelchair Propulsion

Principal Investigator: Kenton R. Kaufman, Ph.D.
Project Coordinator: Brian Kotajarvi — kotajarvi.brian@mayo.edu

Figure 22: (top) Temporal distance variable
Figure 23: (bottom) Wheel angle variables

Upper extremity pain and dysfunction are common among people who use manual wheelchairs for mobility. For example, surveys involving as many as 450 wheelchair-based individuals find that as many as 73% report some degree of chronic upper extremity pain, which they attribute primarily to wheelchair propulsion and transfers.

Individuals with paraplegia are particularly active wheelchair users and, when questioned, report prevalence of shoulder, elbow, and wrist/hand pain between 30% and 65%, with the shoulder the most common site of involvement. These issues have not gone unnoticed and the biomechanical analysis of manual wheelchair propulsion has become increasingly common over the last decade. The aim of this research is twofold. First, to improve propulsion mechanical efficiency and second, to gain better understanding of the wheelchair-user interface to address the musculoskeletal problems associated with wheelchair use.Results showed that the experienced users demonstrated prolonged stroke distance, decreased stroke frequency, longer push time, and a longer push angle than the inexperienced group (Fig 22-23).

A shorter distance between the axle and shoulder (low seat height) resulted in the highest push times and push angle for both groups. Propulsion efficiency as measured by the fraction of effective force did not significantly change with seat position. It was concluded that propulsion experience may play a major role in minimizing peak handrim loads.