The Effects of Biological Sex on Glenohumeral Joint Motion, Force, and Moment Variability during Pediatric Manual Wheelchair Propulsion

Abstract

Research Objectives To assess the biological sex-related differences in three-dimensional glenohumeral joint motion, force, and moment variability in pediatric manual wheelchair users with spinal cord injury. Design Cohort, prospective, cross-sectional. Setting Motion Analysis Lab at Shriners Hospital for Children - Chicago. Participants Nine female and 11 male pediatric manual wheelchair users with spinal cord injury (mean±SD age: 14±4.4 years). To be eligible, participants were required to be under 21 years of age and use a manual wheelchair as their primary mode of mobility. Interventions Participants propelled their personal wheelchair equipped with a Smartwheel using a self-selected speed and stroke pattern. Upper extremity kinematics and kinetics data were measured in a single experimental session. Main Outcome Measures Variance of three-dimensional glenohumeral joint motions, forces, and moments. Results Several biological sex-related differences in kinematic and kinetic variance were found, although no differences in glenohumeral joint kinematics or kinetics were observed. Male participants exhibited greater variance in glenohumeral joint adduction/abduction and flexion/extension ranges of motion, peak joint adduction and external rotation angles, and peak maximum anterior force and superior force (all p≤0.001). Conversely, females exhibited greater variance in peak glenohumeral joint flexion and abduction moments (both p < 0.001). Conclusions Biological sex-related differences in variability of glenohumeral joint motions, forces, and moments exist in pediatric manual wheelchair users with spinal cord injury. Female pediatric manual wheelchair users may be at an increased risk of shoulder pain and pathology due to the combination of decreased variability in glenohumeral joint motions and forces, potentially leading to increased repetitive strain injuries. Author(s) Disclosures No conflicts of interest to declare. To assess the biological sex-related differences in three-dimensional glenohumeral joint motion, force, and moment variability in pediatric manual wheelchair users with spinal cord injury. Cohort, prospective, cross-sectional. Motion Analysis Lab at Shriners Hospital for Children - Chicago. Nine female and 11 male pediatric manual wheelchair users with spinal cord injury (mean±SD age: 14±4.4 years). To be eligible, participants were required to be under 21 years of age and use a manual wheelchair as their primary mode of mobility. Participants propelled their personal wheelchair equipped with a Smartwheel using a self-selected speed and stroke pattern. Upper extremity kinematics and kinetics data were measured in a single experimental session. Variance of three-dimensional glenohumeral joint motions, forces, and moments. Several biological sex-related differences in kinematic and kinetic variance were found, although no differences in glenohumeral joint kinematics or kinetics were observed. Male participants exhibited greater variance in glenohumeral joint adduction/abduction and flexion/extension ranges of motion, peak joint adduction and external rotation angles, and peak maximum anterior force and superior force (all p≤0.001). Conversely, females exhibited greater variance in peak glenohumeral joint flexion and abduction moments (both p < 0.001). Biological sex-related differences in variability of glenohumeral joint motions, forces, and moments exist in pediatric manual wheelchair users with spinal cord injury. Female pediatric manual wheelchair users may be at an increased risk of shoulder pain and pathology due to the combination of decreased variability in glenohumeral joint motions and forces, potentially leading to increased repetitive strain injuries.