The Kinetic Chair in Overhand Throwing

With an estimated 6 million youth players worldwide, baseball enjoys wide popularity. Overhand throwing is an essential part of the game. All defense players on a team must throw and, in particular, pitchers throw a combined 200-400 pitches per game. As a result, participants routinely seek to increase their throwing efficiency. This repetitive action strains muscles and tendons putting players at risk for injury, with over 50% of all athletes experiencing arm pain [1]. To understand overhand throwing practice and efficiency, we report here on a study of 17 youth throwers (ages 10-16). The throws were captured using high-speed, 3D videography. (EMG data were simultaneously captured but will not be presented here.) The captured motion was studied for each body segment as a function of time to determine the flow and timing of kinetic energy through each thrower’s kinetic chain from start to ball release. Results indicate a highly disordered kinetic chain among youth throwers. The role of kinetic chain order/disorder and the importance of specific body segments will be discussed.



[1] Zaremski, J. L., Zeppieri, G., & Tripp, B. L., 2019, J. Athl. Train, 54, 10, 1030