A23 Forward Dynamical Analyses of the Upper Limbs for Generating Bat Head Speed in Baseball Batting
Details
The purpose of this study was to quantify the contribution of the upper limb joint torques and shoulder joint reaction force to the bat head speed during baseball batting motion. The upper limb segments and bat were modeled as a system of seven rigid segments, and each elbow joint was modeled as a one-axis revolute joint to consider the degree of freedom (DOF) of the joint. Each hand was considered to be connected with the bat through zero DOF joint. The equation of motion with respect to the upper limbs and bat was obtained from the equation of motion for each segment and from equations for constraint condition in which adjacent segments are connected by joint. The dynamic contributions of the joint moments, shoulder joint force, motion dependent term and gravity term to the bat head speed were derived from the dynamic equation of the system. Collegiate male baseball players' motion were captured by V1C0N 612 system (9 cameras, 250Hz) and kinetic data of each hand were collected with an instrumented bat with strain gauges (1OOOHz). From the results, not only joint moments but also motion dependent term make significant role for generating bat head speed during forward swing motion in baseball batting.
