The effect of pushing and pulling movements when propulsion a manual wheelchair on upper limb kinematics and muscle activity in people with spinal cord injury

PURPOSE: This study aimed to examine differences in upper limb kinematics and muscle activation between pushing and pulling propulsion methods during manual wheelchair use in individuals with spinal cord injury (SCI). MATERIALS AND METHODS: Twenty manual wheelchair users with SCI participated in this study. Upper limb joint kinematics were assessed using a three-dimensional motion capture system with ten VICON cameras, and muscle activity of eight upper-limb muscles was measured using wireless surface electromyography. Participants performed wheelchair propulsion using both pushing and pulling methods with a two-way propulsion system. RESULTS: Compared with pushing propulsion, pulling propulsion resulted in significantly longer propulsion time and greater ranges of motion in the shoulder and elbow joints. In addition, pulling propulsion elicited significantly higher activation of posterior upper-limb and trunk muscles, whereas pushing propulsion predominantly activated anterior shoulder muscles. CONCLUSIONS: Pushing and pulling propulsion methods produce distinct upper limb kinematic and muscle activation patterns in manual wheelchair users with SCI. Pulling propulsion promotes greater posterior muscle engagement and joint mobility, suggesting its potential as an alternative propulsion strategy to redistribute upper limb muscular load during wheelchair use.