Comparison of shoulder kinetics between running overhead throws with circular and whip-like wind up in elite handball players.

Introduction: The aim of the study was to compare shoulder kinetics between the whip-like and circular wind-ups in running throws in handball. Methods: Twenty-five elite handball players performed running throws with a circular and whip-like wind up while a markerless motion capture system consisting of eight cameras sampling at 250 Hz measured and calculated ball velocity, joint angle, angular velocity, shoulder torques and force during the throws. Results: The main findings were that peak ball and maximal angular external shoulder velocity were higher with the circular wind up together with time of occurrence to closer ball release of peak external rotation torque and peak posterior shear forces compared with the whip-like wind up, while a larger external shoulder rotation angle with a earlier time of occurrences was observed with the whip-like wind up. Discussion: It was concluded that although differences in shoulder kinematics between the two wind-ups were observed it did not result in differences in peak shoulder torque and forces, only in timing. Thereby, both throws seem to cause similar stress upon the shoulder. Thereby, both throws seem to cause similar stress upon the shoulder. While no statistically significant differences in peak shoulder torques and forces were observed between techniques; however, due to the sample size, variability in throwing experience, and the absence of equivalence testing, these findings should not be interpreted as evidence that both techniques impose equivalent shoulder stress.