Trunk EMG during tennis forehand stroke

• Main Authors: Tai, Yu-Lin, 戴幼琳
• Other Authors: Hsieh, Shen-Yu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/66289612655402860415

碩士 === 國立臺灣師範大學 === 運動科學研究所 === 101 === Purpose: To investigate the change of electromyography (EMG) on trunk muscles during a tennis forehand stroke in different stances and directions. Methods: Twelve advanced males tennis players (right handed) performed two stances (open & square stance) and directions (crosscourt & down the line) forehand stroke. The left and right external oblique (LEO & REO), latissimus dorsi (LLD & RLD), and erector spinae (LES & RES) EMGs were collected and compared. The image time of every motion recorded by CASIO digital camera was divided into the preparation, acceleration and follow through phases. A 3-way ANOVAs of repeated measures (α = .05) and LSD for posteriori comparison were used for analysis. Results: The LEO muscle activation was affected by directions. The EMG of crosscourt hits was greater than down the line hits. The interaction of directions and phases impacted on REO, while LES was influenced by the interaction of stances and phases, but they both were no significant in three phases. Also, six muscles were affected by phases. The activation in the acceleration phase were the hightest, except for the LES, the transforming percentage of peak was greater in the preparation phase to the follow through phase, others five muscles changed from the follow through to the preparation phase. Conclusion: It’s important to train LEO muscle to intensify forehand drive crosscourt. During a tennis forehand stroke, LES muscle will activate first. It is the key point to start the force for the trunk with forward racket swing.