Abstract

Neuromuscular and kinematic patterns during the tennis forehand have been studied extensively. However, no one has evaluated potential upper-extremity kinematic changes during the forehand as ball speed increases. The purpose of this study was to evaluate changes in shoulder and trunk kinematics as forehand ball speed increased, in an attempt to better understand how kinematics may promote forehand ball speed. Peak trunk rotation angle, shoulder horizontal abduction/adduction and internal/external rotation angle, and corresponding angular velocities were measured between initial backswing and ball contact during forehands that were performed at three different speeds (50%, 75%, and 100% of maximal post-impact ball speed). Between-speed differences were observed for all dependent variables. Internal humeral rotation velocity increased by 136% (from 477°/s to 1128°/s) while trunk rotation velocity increased by 91% (from 164°/s to 313°/s) and trunk rotation angle increased by only 26% (from 46° to 58°) as forehand ball speed increased from slow to fast. Two primary conclusions can be drawn from these results: (1) trunk and upper arm rotation (adduction and internal rotation) are important to produce forehand ball speed, and (2), increased joint angular velocity may be more important than altered joint position when attempting to produce maximal forehand ball speed.

Degree

College and Department

Life Sciences; Exercise Sciences

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