Influence of Sports Equipments on Human Arm.

Impacting on muscles is a normal phenomenon when a ball strikes a racket or a bat during playing tennis or baseball. It causes vibration, which propagates to human body, especially, hand and arm. Vibration is not desired because it may be a cause of the tennis elbow injury or fracture. So, designing of sports equipments is very important to avoid these injuries of players. In this study, the influence of sports equipments on the muscles and skeleton of human arm during impact is focused. A case is considered where a ball strikes against a tennis racket, which is fixed by hand and arm. A multi-degree-of-freedom model of the ball and racket is constructed by finite element method, and human hand, lower arm and upper arm are considered as an individually rigid linked model. The joint moments are calculated when a ball strikes against a racket using modal analysis technique. Then, some muscles are adopted and a musculoskeletal model is constructed. The muscular forces are identified such as to satisfy the joint moments by the optimization method. Finally, the influence of property of racket on the muscles is investigated. [ABSTRACT FROM AUTHOR]