| The purpose of this study was to determine in-depth 3-D kinematic descriptors of the fastball, windmill softball pitch, and to investigate the sequentiality and simultaneity among three different skill levels. A total of 17 right handed female windmill softball pitchers volunteered to participate (5 advanced, 6 intermediate, and 6 novice). Participants were videoed while performing five windmill style fastball pitches (only one trial was chosen for analysis). In addition, participants underwent anthropometric, height, and weight measurements as well as performing two standardized power tests: vertical jump and the arm Wingate. Three-dimensional motion analysis was performed through Kwon 3D analysis system (Visol, Inc., Seoul, Korea).; Orientation angles (OA) of the joints and their first time-derivatives were obtained based on segmental reference frames to determine the joint motion patterns: trunk (left/right rotation), shoulder (flexion/extension, adduction/abduction, internal/external rotation), elbow (flexion/extension), forearm (pronation/supination), and wrist (ulnar/radial deviation and flexion/extension). Based on linear velocity (LV) of the ball, wrist, elbow and shoulder; individual limb contributions were computed for the upper arm, forearm and hand.; Demographic results revealed an average ball velocity for the advanced, intermediate, and novice groups of 21.6m/s, 20.7m/s, and 15.4m/s respectively. Resulting stride lengths constituted 62%, 71%, and 62% of individual standing height for the three groups of advanced, intermediate, and novice participants. The resulting kinematic analysis revealed definite proximal to distal sequence of angular deceleration within the arm segments prior to ball release. It was also revealed that there was a definite proximal to distal sequence of segmental contributions to ball velocity among intermediate and advanced pitchers. Results revealed that as experience digresses towards a more novice pitcher, the greatest speed is still at the most distal end, however the contributions are more equally represented throughout the link segment. It was concluded that the advanced windmill softball pitcher possesses the critical element of proper sequencing of segments in attempt to achieve the greatest velocity at the most distal segment for the production of the greatest ball velocity. |
