Upper extremity pain (UEP) is a substantial problem in individuals who depend on manual wheelchair use for mobility. The prevalence of shoulder pain in manual wheelchair users (MWUs) with spinal cord injuries (SCI) is between 30% and 70% and mononeuropathies such as carpal tunnel syndrome have a prevalence between 40% and 60%. Because the upper extremity is essential for almost all activities in individuals with SCI, UEP can cause serious secondary disability. Research into the cause of UEP has been limited, and virtually no studies have looked at intervention or prevention. In this study we will test the hypothesis that UEP and pathology are related to specific joint angles, moments and force occurring during manual wheelchair propulsion. Our specific aims are: 1) to determine specific biomechanical factors which differentiate MWUs with and without pathological or clinical findings in the upper extremities, 2) to further define the prevalence of upper extremity pain and pathology in manual wheelchair users and its relation to length of time with disability, 3) to gain further insight into the progression over time of upper extremity injuries in individuals with new disability. With this knowledge, it may be possible to improve wheelchair fit, prescription and training in such a way as to prevent injuries. These improvements with lead to less secondary disability, less cost and greater productive life.