Data processing and Statistical Analysis

Filtered data was used as input for the 15-segment biomechanical model. All parameters obtained from the VICON motion capture system and biomechanical modeling were analyzed using SPSS Statistics v.22.0 (SPSS Inc., Chicago, IL). Results are presented using descriptive statistics. Further, independent t-tests were applied to contrast differences between novice and skilled players on both smash quality and movement parameters. Statistical significance was defined as p < 0.05. Indications of an ‘increase’ in a parameter (percentage change) were calculated using the following formula [(large value-small value)/small value]. This formula was also used for determining the percentage differences between groups.

Correlations were computed within subjects between X-factor and Vmax, X-factor and H_p-n, X-factor and A_shuttle, X-factor and the ROM of the shoulder (flexion/extension, abduction/adduction, and twist), elbow (flexion/extension) and wrist (flexion/extension), and X-factor and PM using the Pearson correlation coefficient (Lawrence and Lin, 1989; Stigler, 1989). The results of correlation analyses were used to identify factors related to the quality of the smash.