THE EFFECT OF CHANGING CENTER OF MASS AND WEIGHT BASEBALL BAT ON SWING PERFORMANCE AND MUSCLE ACTIVATION

• Main Authors: Chen, Chun-Yang, 陳俊揚
• Other Authors: Chung, Pao Hung
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/8cfxmn

碩士 === 臺北市立大學 === 運動器材科技研究所 === 103 === Purpose: To explore the effect of baseball bats, under identical moment of inertia (MOI) with various center of mass (COM) and weight on swing performance and muscle activation. Methods: Twelve college Level I baseball male players were recruited as subjects, who performed swing tests under four levels of MOI (very small, small, middle, large) with four different weights of wooden baseball bats and one adjustable COM of customized baseball bat. Each test processed three trials with the subject’s maximal effort. An image analysis system was used to analyze the swing performance, and the muscle activation of four muscle on leading hand was analyzed by electromyography. Results: No significant swing performances were found between the baseball bats of changing COM and weight under identical MOI (p>.05). The faster swing velocity was found along with the smaller MOI (p<.05), and two different types of baseball bat had the same phenomenon. Conclusion: Whether to change the center of mass or weight of baseball bat have the same swing performance, as long as the same moment of inertia.