Upper-limb kinematics during push and pull configurations of a dual-propulsion wheelchair in individuals with spinal cord injury

OBJECTIVES: This study compared upper-limb kinematics and propulsion patterns between the push and pull propulsions of a detachable dual-propulsion wheelchair in individuals with spinal cord injury. METHODS: Sixteen men with spinal cord injury performed 10-m straight-line trials at a self-selected speed under laboratory conditions. Gear ratios of 1:1 and 1:2 were applied to the push and pull propulsion, respectively. Upper-limb and trunk movements were recorded using a 10-camera Vicon motion capture system. Propulsion time and speed, shoulder and elbow ranges of motion, propulsion angle, trunk movement, and wrist trajectories were analysed. RESULTS: The pull propulsion produced a longer propulsion time, lower speed, and greater shoulder and elbow ranges of motion and propulsion angle during propulsion. During the recovery phase, joint ranges of motion were greater in the push propulsion. Trunk sway at the key events did not differ between the two propulsion configurations, while descriptive variations in trunk and wrist movement patterns were observed across participants. CONCLUSION: The two configurations elicited distinct upper-limb kinematic patterns. However, because propulsion direction and gear ratio were mechanically coupled and propulsion speed and mechanical workload were not standardised, these findings should be interpreted as configuration-specific kinematic differences rather than independent effects of propulsion direction. Further studies should assess muscle activity, musculoskeletal loading, pain, fatigue, and propulsion efficiency under matched gear-ratio and standardised speed or power-output conditions.