Overground-Propulsion Kinematics and Acceleration in Elite Wheelchair Rugby

Purpose: Maximal acceleration from standstill has been identified as a key performance indicator in wheelchair rugby; however, the impact of classification and kinematic variables on performance has received limited attention. This study aimed to investigate kinematic variables during maximal acceleration, with level of activity limitation accounted for using sport-classification scores. Methods: Based on their sporting classification scores, which reflect combined trunk, arm, and hand function, 25 elite wheelchair rugby players were analyzed in high-, mid-, and low-point groups before completing five 5-m sprints from a stationary position. Inertial measurement units and video analysis were used to monitor key kinematic variables. Results: Significant differences in kinematic variables were evident across the classification groups, particularly for the first stroke-contact angle (1-way ANOVA F-2,F-122 = 51.5, P<.05) and first stroke time (F-2,F-124 = 18.3, P<.05). High-point players used a first stroke-contact angle that was closer to top dead center of the wheel than either other group, while also using a shorter overall stroke time than low-point players. A linear mixed-effects model was used to investigate how kinematic variables influenced performance, with results suggesting that increased release angles (ie, farther around the wheel) and decreased stroke angles resulted in larger peak accelerations. Further investigation revealed that these results are likely influenced by strong relationships for the high-point group, as there was often no clear trend evident for midpoint and low-point groups. Conclusion: Findings show that various propulsion approaches exist across classification groups, with this information potentially informing individual wheelchair setups and training programs.