本研究以高中健康青棒投手7名，利用Cybex-6000做為測試儀器，在五種不同角速度30°60°90°180°240°進行向心、離心肌力最大力矩值和各種不同肌力比值雙側差異比較，和肩關節內轉、外轉、全關節活動度，以及功能性肌力比值（外轉離心肌力/內轉向心肌力）的測定，統計方法採用Paired t test考驗雙測間的差異。在五種不同角速度間，速度-力量曲線直線迴歸相關，統計方法採用Linear regression，並以Tukey法進行事後比較。
我們發現：肩關節內轉、外轉、全關節活動度雙側間無明顯差異存在(P＞.05)。在向心最大力矩值測驗上，肩關節向心外轉向心肌力在角速度60度時，有雙側顯著差異存在(p<.05)；其他角速度時向心肌力測驗項目皆無雙側差異存在。肩關節離心肌力各項表現，雙側間皆無顯著差異存在。不論在何種角速度或測試項目，各種向心肌力皆顯著小於離心肌力(p<.05)。
向心外轉/內轉肌力比值在角速度60度和180度時，雙側有顯著差異存在(p<.05)；其他不同角速度間，向心外轉/內轉肌力比值在慣用側有小於非慣用側的趨勢存在；而離心肌力比值，雙側間統計上無明顯差異存在。功能性肌力比值（外轉離心肌力/內轉向心肌力），本研究結果發現雙側間差異未達顯著，但慣用側的功能性肌力比值皆有小於非慣用側的趨勢存在，約有20個百分點的差異，但雙側間統計上無明顯差異存在。在五種不同為速度間，各種向心肌力最大力矩值，隨著角速度增加而力矩值明顯的呈現直線性減少(p<.05)。在五種不同角速度間，各種離心肌力最大力矩值，隨著角速度增加而力矩值有直線性下降的趨勢，但在角速度240度時力矩值不降反昇。
功能性肌力比值是首次被使用在健康投手研究上，本研究首次建立出健康青棒投手的功能性肌力比值資料，以供未來研究者或復健訓練時的參考數據。

The purpose of this investigation was to measure shoulder strength and range of motion among high school pitchers. Comparisons were made between dominant and non-dominant sides. Seven healthy high school varsity baseball pitchers participated in the study. The purpose and the procedures of this study were explained to the subjects and an inform consent form was signed by every subjects. A Cybex-6000 isokinetic dynamometer was used to measure shoulder range of motion, peak torque for internal rotation and external rotation for both concentric and eccentric strength. Five testing speeds were used for the measurement of the peak torque (30°, 60°, 90°, 180°, 240°/sec). A functional strength ratio was then determined by using the peak torque of eccentric external rotation over concentric internal rotation in this study. Paired t-tests were used to compare the peak torque and range of motion between dominant and non-dominant side and between concentric and eccentric peak torque at the same isokinetic testing speed. The relationship between contraction speed and peak torque was calculated by linear regression.
The results of this investigation showed that the range of motion measurements were not significantly different (p>.05) between dominant and non-dominant sides. At the speed of 60°/sec test, the peak torque of concentric external rotation in the dominant was significantly (p<.05) larger than the peak torque in the non-dominant side, but the rest of the data did not show statistical significant differences between both sides.
In the eccentric peak torque strength tests, the mean internal rotation peak torque of the dominant side was larger than the mean strength of the non-dominant side, but the mean external rotational peak torque of the non-dominant side was larger than the mean strength of the dominant side; however, the differences did not reach statistical significant level. The out put of the eccentric contraction strength was always larger than the concentric contraction strength at all testing speeds (p<.05).
In the comparison of strength ratio (external rotation strength/internal rotation strength), non-dominant side was found significantly larger than the dominant side at the speed of 60° and 180°/sec concentric strength ratio. In the measurement of functional ratio, non-dominant side was 20% more than the dominant side. The data also showed that there was a negative linear relationship (Linear regression) between concentric peak torque strength and isokinetic contraction speeds. However, a linear relationship between the eccentric peak torque strength and isokinetic contraction speeds could not be found.