Introduction: Throwers perform several overhead throws that involve precise coordination of all body segments (MacWilliams, Choi, Perezous, Chao & McFarland, 1996). “Pappas et al. describe baseball throwing as a sequential activation of body parts through a connecting segment that begins with the contralateral foot and progresses through the trunk to the rapidly accelerating upper extremity” (MacWilliams et al., 1996). There is growing concern among sports medicine professionals that the number of baseball pitchers with elbow injuries appears to be increasing. Baseball pitchers use multi-joint movements, which are joints that rotate due to muscle torque, gravity, and interaction. Previous research suggests that the main risk factor may be due to muscle overuse, such that the risk of elbow pain is related to the number of pitches thrown in a game and in a season (Fleisig, Weber, Hassel & Andrews, 2009). Therefore, to minimize future injuries/risks, an appropriate experiment must be performed to determine which potential changes in muscle function would be most beneficial for learning an expert throwing motion (Jindrich, 2014). .* FOCUS ON THE UPPER EXTREMITY*There have been some studies that suggest that practicing key player muscle forces (wrist, elbow and shoulder) in opposing and modulating with interaction and gravity torques in the upper extremity should cause an improvement in throwing ability (Hirashima, Kudo, Watarai, & Ohtsuki, 2006). As in the research of Masaya Hirashima and his colleagues, they found that participants used the interaction torques to generate greater velocity during shoulder internal rotation, elbow extension... in the center of the card... l players . J Neurophysiol , 680-691. doi: 10.1152/jn.00348.2006Jindrich, D. (2014). Segmental dynamics in movement. Kine 301: Case Study 2, Kinesiology,Cal State San Marcos, San Marcos.MacWilliams, B., Choi, T., Perezous, M., Chao, E., & McFarland, E. (1996). Retrieved from http://ajs.sagepub.com/content/26/1/66.short Posner, M., Cameron, K. L., Wolf, J. M., Belmont, P. J., & Owens, B. D. (2011). Major League Baseball Injury Epidemiology. The American Journal of Sports Medicine, doi:10.1177/0363546511411700Yamada, Y., Yamashita, D., Yamamoto, S., Matsui, T., Seo, K., Azuma, Y., Kida, Y., Morihara,T. , Kimura, M. (2013). Whole-body and segmental muscle volume are associated with ball velocity in high school baseball pitchers. The American Journal of Sports Medicine, doi:10.2147/QAJSM.S42352. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/24379713