本研究目的在於驗證高爾夫揮桿旋轉中心為頸椎第七節C-7的內部中心，以此旋轉中心來被視與擊球準確的關係。此內部中心點亦位於旋轉軸的頂點，因此定義為軸頂點(top spot)，並探討此旋轉中心軸頂點與擊球準確度的關條。在高爾夫擊球過程中，軸頂點是移動範團最小的部位，根據此理論，欲控制打擊使球與打擊面甜區(sweet spots)精確撞擊，必需要有兩項主要因素：一為軸頂點最少的左右(水平面)移動範圍，旋轉穩定度越高則水平位移越少。二為正確的軸頂點高度(垂直面)以做為正確的揮桿半徑，高度變化的差別小則揮桿半徑越精確。實驗方法主分為打擊面的球印座標登記、旋轉中心的位移位置攝錄、以及SPSS分析比較其相關性質。一、打擊面球印位置的測試。將打擊面區分為水平座標Xl、X2、X3與垂直座標Yl、Y2、Y3，甜區為X2Y2，籍以蒐集碰撞時球印在打擊面的座標位置。二、C-7位移位置的攝錄。4名高爾夫選手、4名初學者，進行每人的下揮桿的測試，他們穿著黑色高領長袖緊身衣，光點貼於雙肩以及環繞在頸椎第七節的後、左、右位置，數位攝影機(/120sec)攝取受試者正上方(水平面)、正後方(垂直面)的動作影像，經Ariel Dynamics影像軟體系統，分析軸頂點在水平面座標、垂直面的移動位置。三、SPSS for Windows統計軟體，進行球印在打擊面密區與非密區座標的揮桿筆數統計，然後比較出軸頂點位置的差異性。結果顯示：撞擊的球印座標所對應軸頂點高度差與旋轉穩定度皆達顯著水準(p<.05)，此說明了精確擊球時，軸頂點的高度差及旋轉穩定度，有顯著關係。

Purpose: To verify the position of the cervical curvature C-7 as an rotation center during a golf swing by examining the correlation between the displacement of rotation center and the hitting accuracy of a ball on the club face. The position of the rotation center was defined as the "top spot on the axis" because it happens to be the apex of the rotation axis, and it was assumed to be the steady point during a golf swing. Under this assumption, there are two main factors that control the accuracy of hitting a ball on the sweet spot of the club face. One is the stability of shoulder (trunk) rotation indicated by the least displacement of the top spot on the horizontal plane---"rotation stability" and the other is the correct height of the top spot on the vertical plane to be the correct length of swing radius as to hit the ball on the sweet spot---"height difference". Study method: (1)The recording of the ball trace on the club face. Horizontal axes (X1, X2, X3,) and vertical axes (Y1, Y2, Y3) were established to mark on the club face (sweet spot area was X2Y2). This was then used to record the ball tracing areas. (2)The image displacement of the rotation center (top spot). Four varsity players and four beginners participated in the study. Each subject swung the golf club 40 times. They dressed in black tighten wear and sliver marks were attached to their neck around the C-7 and also on two shoulder points to be used as reference points for pictures taken by the digital cameras (1/120sec). The superior view camera was to observe the rotation stability of the top spot on the horizontal plane and the posterior view camera was used to observe the height difference of the top spot on the vertical plane. Images of the rotation center were digitized by Ariel Dynamics software system APAS. (3)The statistical analysis. SPSS for Windows 8.0 was used to compare the variation (difference) and correlation of the rotation stability and height difference of the top spot between the inside and outside sweet spot. Reslults: Peason's correlation analysis showed a statistically significant (p< .05) relationship between the rotation stability and hitting accuracy as well as between the height difference and hitting accuracy.