Kinematic analyses of seated throwing activities with and without an assistive pole

Abstract

In Paralympic seated throwing events, the athlete can throw with and without an assistive pole. This study aimed to identify and compare performance-related kinematic variables associated with both seated throwing techniques. Twenty-nine non-disabled males (21.9 ± 2.6 years) performed 12 maximal throws using a 1-kg ball in two conditions (no-pole and pole). Automatic 3D-kinematic tracking (150 Hz) and temporal data were acquired. There was no significant difference between ball speeds at the point of release between conditions (no-pole = 12.8 ± 1.6 m/s vs. pole = 12.9 ± 1.5 m/s). There were four kinematic variables that were strongly correlated with ball speed when throwing with or without an assistive pole. These variables were elbow flexion at the start phase (pole r = .39 and no-pole r = .41), maximum shoulder external rotation angular velocity during the arm cocking phase (pole r = .42), maximum shoulder internal rotation angular velocity during the arm acceleration phase (pole r = .47), and should internal rotation angular velocity at the instant of ball release (pole r = .40). The pole clearly influenced the throwing technique with all four strongly correlated variables identified in this condition, compared to only one during the no-pole condition. When using the pole, participants produced significantly higher shoulder internal rotation angular velocities during the arm acceleration phase (pole = 367 ± 183°/s vs. no-pole = 275 ± 178°/s, p < .05) and at the instant of ball release (pole = 355 ± 115°/s vs. no-pole = 264 ± 120°/s, p < .05), compared to throwing without the pole. These findings have implications for the development of evidence-based classification systems in Paralympic seated throwing, and facilitate research that investigates the impact of impairment on seated throwing performance.