Scapular muscle recruitment patterns during various types of baseball pitches in high school pitchers

• Main Authors: Chen, Wei-Ting, 陳威廷
• Other Authors: Tsai, Yung-Shen
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/649y68

碩士 === 臺北市立大學 === 運動科學研究所碩士在職專班 === 106 === Objective: To evaluate the scapular muscle which includes upper trapezius, lower trapezius and serratus anterior muscle recruitment patterns during various types of baseball pitches in high school pitchers, the different baseball pitches includes (1)curveball, (2)slider, (3)fastball and (4)change up. Methods: Ten subjects were asked to perform the four different types of baseball pitches in the laboratory, and the signal of upper trapezius, lower trapezius and serratus anterior contraction were collected by surface EMG in the different stage of pitching (stride, arm cocking and arm acceleration) . The signal of muscle contraction was normalized by the maximal voluntary isometric contraction of each muscle, and a high-speed camera was utilized to record the pitcher’s motion during the different stage of pitch. Wilcoxon sign rank test was used to compare the variations of different types of pitches and stage, significant level was set at p<0.05. Result: There’s no significant difference between the scapular muscle recruitment pattern in the four types of pitches. But the intensity of muscle contraction in arm acceleration phase was similar to arm cocking phase, and both of them are stronger than the intensity in stride phase, but the intensity would reach the maximum in the slider and curveball in lower trapezius and serratus anterior, this result indicates that there are differences between slider and curveball. Conclusion: The result of this study shows that scapular muscle recruitment pattern has no significant difference in the four types of pitches, and it indicates that scapular muscle would provide the similar stability in the four types of pitches.