Objective: The aims of this study were (1) to identify differences in trunk muscle strength and balance among various classes of wheelchair basketball (WCB) players and (2) to determine if trunk muscle strength and balance correlate with the current observation-based classification of WCB players.
Design: Isometric trunk strength and balance (limits of stability) were objectively quantified in 42 male WCB players. Principal component analysis was used to synthesize a battery of strength and balance measures into a single, composite score of trunk function. The K-means clustering algorithm was then used to generate an objective classification system by stratifying players into 4 classes based on their trunk function.
Results: Results indicated that there were significant differences in trunk muscle strength and balance between various classes of WCB players (P < 0.05), such that the mean peak trunk extensor and flexor torque and limits of stability indices increased progressively according to the players' classes. There was also a significant correlation between observation-based WCB classification and principal component analysis cluster analysis-based WCB classification (ρ = 0.785, P < 0.05).
Conclusions: This study provides novel evidence indicating that trunk strength and balance differ among various classes of WCB players, and objective measures of trunk function correlate positively with the current observation-based WCB classification system.