Shoulder mechanical impingement risk associated with manual wheelchair tasks

Shoulder mechanical impingement is a possible contributor to shoulder pain in individuals with spinal cord injury (SCI) who use a manual wheelchair (MWC). Biplane fluoroscopy and model-based tracking were used to measure the subacromial space during daily tasks in MWC users, and impingement risk was compared based on frequency and amount of rotator cuff tendon compression. Scapular plane elevation (scaption) and propulsion, but not pressure reliefs, were defined by periods of impingement in most participants. Impingement risk was greater during scaption than propulsion, and did not vary with load/resistance. These findings should be considered in terms of frequency of, and technique used to complete, daily tasks.