高爾夫揮桿動作中下桿啟動之下肢肌電訊號分析

Electromyographic Analysis on The Musculature of the Lower Extremity During the Golf Downswing

近代高爾夫揮桿技術的研究，特別是針對下桿動力與身體表現，更是被廣泛的提出來討論。但是對於影響擊球效能極大的下桿啟動之研究卻極少，本研究旨在探討高爾夫運動員在揮桿的過程中，下桿啟動時之肌電時序，並比較分別使用7號鐵桿與1號木桿時，在下桿過程中兩者間的左腳地面反作用力之差異。六位差點在2～7（桿）的男性右打者，分別使用與7號鐵桿與1號木桿，在實驗室兩塊測力板（force plate）上進行10次揮桿打擊貼反光紙之球，同步以六架CCD攝影機擷取貼在球桿上與打擊球之3個反光球訊號，以及收集貼在受測者左腳腿部的七個表面電極（1000Hz，Surface electrode）的肌電訊號（含臀大肌、臀中肌、股直肌、股二頭肌、內收大肌、脛前肌與腓腸肌）。得到在使用7號鐵桿與1號木桿下桿時的左腳肌肉的活化次序呈現相當一致的趨勢。下桿啟動早於桿頭的回轉時間與至擊球瞬間的下桿時間幾乎是一樣的。在擊球瞬間時，左腳所承受的地面正向力，使用7號鐵桿約為體重的102.0±7.2﹪，1號木桿約為體重的112.1±9.0﹪，兩者有明顯差異（P＜.05）。研究資料顯示，下桿動作是由左膝伸展與左大腿的向外迴旋結合作為啟動，引發臀部的迴轉，進而穩定與支撐被牽動的軀幹以發揮擊球效率。下桿啟動時，由左腳大腿與臀部的大肌肉開始產生活動，在擊球瞬間，旋轉力矩急速的增加時，左腳臀大肌、股二頭肌與內收大肌的明顯活動，在提供這個旋轉力矩時是扮演著極重要的角色。本研究發現：使用7號鐵桿與1號木桿對於高爾夫下桿的啟動動作與肌肉活化次序相當一致，擊球瞬間時，左腳承受的地面正向力有明顯的影響，顯示下桿啟動的左腳動作有相當一致的順序且支撐身體穩定揮桿的左腳力量極為要。這個發現，使我們進一步了解到下桿啟動的技巧，不僅支撐著流暢且符合力學之身體旋轉，而且是發揮揮桿穩定與擊球效能的重要基礎。In the field of sports biomechanics, the motion pattern of golf swing and the power of downswing have been extensively discussed, however, very few scholars pay attention to the transition of downswing. The purpose of this study was to investigate 1) the muscles firing sequence of the left lower extremity 2) the ground reaction force of left foot by using the 7-iron club and the driver. Six right-handed golfers with handicaps of 2 to 7 volunteered for this study. In this research, two force plates (1000Hz) and six CCD cameras (120Hz) were applied to record the kinetic data during the golf downswing. Besides, seven surface electrodes (1000Hz) were used to study the seven muscles of the left lower extremity (The Gluteus Maximus, Gluteus Medius, Rectus Femoris, Biceps Femoris, Adductor Magnus, Tibialis Anterior, and Gastrocnemius.) The result demonstrated that the muscle activity of the left lower extremity during the golf downswing had the same sequence between different clubs. Nevertheless, the clubs effected significantly on the ground reaction force of the left foot. It also demonstrated that the left lower extremity motion sequence of the transition supported a flowing and dynamic body rotation. Furthermore, this motion sequence of the transition was fundamental to create a stable swing and an effective impact.