Handrim wheelchair propulsion technique in individuals with spinal cord injury with and without shoulder pain - a cross-sectional comparison

OBJECTIVE: To compare handrim wheelchair propulsion technique between individuals with spinal cord injury (SCI) with and without shoulder pain.DESIGN: A cross-sectional study including 38 experienced handrim wheelchair users with SCI. Participants were divided in a 'shoulder pain' (n = 15) and 'no-shoulder pain' (n = 23) group using the Local Musculoskeletal Discomfort scale. Kinetic and spatiotemporal aspects of handrim wheelchair propulsion during submaximal exercise on a motor-driven treadmill were analyzed. Data were collected using a measurement wheel instrumented with 3D force sensors.RESULTS: After correction for confounders (time since injury and body height), linear regression analyses showed the pain group had a 0.30 s (95% CI, -0.5 to -0.1) shorter cycle time, 0.22 s (95% CI, -0.4 to -0.1) shorter recovery time, 15.6° (95% CI, -27.4 to -3.8) smaller contact angle and 8% (95% CI, -15 to 0) lower variability in the work per push compared to the no-pain group. Other parameters did not differ between groups.CONCLUSIONS: This study indicates that individuals with SCI who experience shoulder pain propel their handrim wheelchair kinematically different from individuals with SCI without shoulder pain. This difference in propulsion technique might be a pain-avoiding mechanism aimed at decreasing shoulder range of motion.