Year, Volume, Issue, Page(s):16, 33, , 34-41
Study used musculoskeletal modeling and forward dynamics simulations of manual wheelchair propulsion to identify compensatory strategies to overcome weakness in individual muscle groups and identify specific strategies that may increase injury risk. Identifying these strategies can provide the rationale for the design of targeted rehabilitation programs aimed at preventing the development of pain and injury in manual wheelchair users. Muscle-actuated forward dynamics simulations of manual wheelchair propulsion were analyzed to identify compensatory strategies in response to individual muscle group weakness using individual muscle mechanical power and stress as measures of upper extremity demand. The simulation analyses found the upper extremity to be robust to weakness in any single muscle group as the remaining groups were able to compensate and restore normal propulsion mechanics. The rotator cuff muscles experienced relatively high muscle stress levels and exhibited compensatory relationships with the deltoid muscles. These results emphasize the importance of strengthening the rotator cuff muscles and supporting muscles whose contributions do not increase the potential for impingement (i.e., the thoracohumeral depressors) and minimize the risk of upper extremity injury in manual wheelchair users.