Individuals who propel wheelchairs have a high prevalence of upper extremity injuries (i.e., carpal tunnel syndrome, elbow/shoulder tendonitis, impingement syndrome). Musculoskeletal injuries can result from overuse or incorrect use of manual wheelchairs, and can hinder rehabilitation efforts. To better understand the mechanisms of upper extremity injuries, this study investigates the motion of the wrist during wheelchair propulsion. This study also examines changes in the variables that occur with fatiguing wheelchair propulsion to determine how the time parameters of wheelchair propulsion and the state of fatigue influence the risk of injury. A two dimensional (2-D) analysis of wrist movement during the wheelchair stroke was performed. Twenty subjects propelled a wheelchair handrim on a motor-driven treadmill at two different velocities (50, 70 m/min). The results of this study were as follows; The difference in time parameters of wheelchair propulsion (cadence, cycle time, push time, recovery time, and PSP ratio) at two different velocities was statistically significant. The wrist kinematic characteristics had statistically significant differences at two different velocities, but wrist radial deviation and elbow flexion/extension had no statistically significant differences. There were statistically significant differences in relation to fatigue in the time parameter of wheelchair propulsion (70 m/min) between initial 1 minute and final 1 minute. The wrist kinematic characteristics between the initial 1 minute and final 1 minute in relation to fatigue had statistically significant differences but the wrist flexion-extension (50 m/min) had no statistically significant differences. According to the results, the risk of musculoskeletal injuries is increased by fatigue from wheelchair propulsion. To prevent musculoskeletal injuries, wheelchair users should train in a muscle endurance program and consider wearing a splinting/grove. Moreover, wheelchair users need education on propulsion posture, suitable joint position, and proper recovery patterns of propulsion.

Objectives: The purpose of this study was to investigate the effects of wheelchair propulsion speed changes on the shoulder impingement syndrome. Method: EMG activity of 5 muscles (biceps brachii, pectoralis major, deltoid anterior, triceps brachii, and trapezius) were recorded with surface electrodes in 24 males during propulsion of three different speed levels on a motor-driven wheelchair treadmill. EMG signal was analysed using root mean square (RMS) values. In order to assure the statistical significance of the results, the one-way ANOVA and a Post Hoc Multiple Comparison were applied at the 0.05 level of significance. Results: The results of this study were as follows: Biceps brachii, and pectoralis RMS value variations of wheelchair propulsion speed between 45m/min and 60m/min, and between 60m/min and 75m/min were not statistically different (p>0.05). Triceps brachii, deltoid anterior and trapezius RMS value variations of wheelchair propulsion speed between 45m/min and 75m/min were statistically different (p<0.05). Conclusions: The risk of impingement syndrome has increased from deltoid muscle contraction growth and trapezoid, triceps brachial muscle endurance decrease when wheelchair propulsion speed rises. To prevent from impingement syndrome wheelchair users should strengthen and endure shoulder muscles. Besides we need education on propulsion posture and suitable position for wheelchair users.