3-DIMENSIONAL KINEMATICS OF THE THROWING ARM DURING THE PENALTY THROWIN WATER POLO

The purpose was to compute the instantaneous contributions of anatomic al rotations of the trunk upper arm, forearm, and hand to ball speed a nd to quantify the three-dimensional angular kinematics of the trunk a nd throwing arm during water polo penalty throws. The largest contribu tors to predicted ball speed \(V-B)'\ at release were forearm extensio n and a counterclockwise twisting rotation of the trunk. Upper arm int ernal rotation contribution to \(V-B)'\ at release was highly variable and exhibited a significant inverse relationship with the upper arm h orizontal adduction contribution to \(V-B)'\ at release (r = -.70). Su bjects with large internal rotation contributions to \(V-B)'\ tended t o have the upper arm in positions of less external rotation, but inter nally rotating at a faster rate, at release. Subjects with large upper arm horizontal adduction contributions to \(V-B)'\ exhibited a trend for faster rates of upper arm horizontal adduction and positions of in creased forearm pronation at release. Findings suggest that a continuu m of technique styles are used by water polo players to produce ball s peed at release.