目的：將肩部肌力及肩關節活動度等兩項最容易影響網球運動者容易發生肩關節傷害的因素合併探討，以了解網球選手肩部肌力及肩關節活動度之間的關係。方法：共招募國內大學甲組健康網球運動員13位，測量肩部肌力與肩關節活動度，所有測試慣用手及非慣用手皆要進行測試。以敘述性統計分析網球選手在肩關節活動度及肩部原始肌力及標準化肌力數值之平均數與標準差。以相依樣本t考驗分析受試者慣用側與非慣用側之肩關節活動度、肌力及肌力標準化之差異；再以皮爾森積差相關分別分析網球選手肩關節活動度及肩部標準化肌力之間的相關性。結果：肩關節外轉角度與肩外展標準化肌力有顯著負相關，兩者間之相關係數為-.583，達中度負相關；肩關節內轉角度與肩內轉標準化肌力同樣有顯著負相關，兩者間之相關係數為-.580，達中度負相關；其餘之肩關節角度與肩部肌力之間均未達顯著差異。結論：國內網球選手肩關節角度及內轉及外轉全角度鬆弛度較國外選手緊，並未有因運動專項造成明顯地關節活動度適應的情形。國內網球選手肩內/外轉肌的肌力比值與國外研究差異不大。

Purpose: The objective of this study was to investigate the associations between muscle strength in shoulders and shoulder joint flexibility, the factors which most likely resulted in a shoulder joint injury in tennis players. Methods: Thirteen elite tennis players from interior universities were recruited to measure their muscle strength in shoulders and shoulder joint flexibility, on both favored and non-favored hands. Via the descriptive statistics, the study analyzed the average and the standard deviation of the players’ shoulder joint flexibility, prime muscle strength in shoulders, and normalized muscle strength. Based on t-test, the study analyzed the difference of the test participants’ shoulder joint flexibility, prime muscle strength in shoulders, and normalized muscle strength on both shoulders. Then it analyzed the relativity between the participants’ shoulder joint flexibility and normalized muscle strength on the basis of Pearson’s Product-Moment Correlation. Results: The research found significant negative correlation between the angles of shoulder joint external rotation and the normalized muscle strength of shoulder abduction. The correlation coefficient between them was -.583, reaching the standard of middle inverse correlation. Besides, it also found significant negative correlation between the angles of shoulder joint internal rotation and the normalized muscle strength of shoulder internal rotation. The correlation coefficient between them was -.580, reaching the standard of middle inverse correlation. However, the research found no significant distinction between the angles of other shoulder joints and muscle strength in shoulders. Conclusions: The study assumed that the slack and angles of interior tennis players’ shoulder joints were smaller than those of foreign players. The ratio value of the interior tennis players’ muscle strength in shoulder internal rotation and external rotation was about 1.10 ± 0.13, which showed no distinction from those in foreign researches.