| Musculoskeletal disorders, fatigue and other problems associated with the use of traditional, hand-rim wheelchairs have been documented in several studies. In response to these problems students in the Mechanical Engineering program at the University of Utah have created three alternative propulsion wheelchair prototypes. The three designs are the hand-lever, track-ball, and four-bar design. These wheelchair prototypes were designed to reduce injuries and fatigue, while maintaining safe, ergonomic function. This study tested and compared these prototypes, as well as a traditional hand-rim wheelchair. Each wheelchair propulsion system was evaluated using a wide spectrum of tests. This allowed the evaluation of each system's strengths and weaknesses. These tests included metabolic evaluation, maneuverability, usability and biomechanical modeling. The metabolic testing revealed that the upper body propulsion systems had lower energy demands than the lower body propulsion systems. Maneuverability testing found that the arm lever and hand-rim systems were the two systems which were most maneuverable. Biomechanical modeling noted that the hand-lever had lower force requirements and lowest joint moments than the hand-rim design and the four-bar had lower force requirements and lower joint moments than the trackball. |
