The Comparison of Scapular Muscle Strength between Collegiate Pitchers and Tennis Players

Shoulder injury was common seen in racquet sports and baseball players. One of the injury factors was weakness of muscles that around the scapulae. Therefore, the purpose of this study was compared the scapular muscle strength between collegiate pitchers and tennis players. Seventeen collegiate pitchers and fourteen male tennis players were recruited to participate this study. All subjects have no any history with upper extremities injuries. The isometric muscle strength of dominated arm was measured by using MicroFet 2 manual muscle tester. The measured scapular muscles included middle trapezium, lower trapezium, serratus anterior, and shoulder internal and external rotators. The values of scapular muscle strength had normalized by subjects' body weight. The independent T test was used to compare the scapular muscle strength of dominated arm between collegiate pitchers (P) and tennis players (T). The results had showed significantly difference between pitchers and tennis players in middle trapezium (P: 0.19 +/- 0.03 vs T: 0.22 +/- 0.03, p<.05), lower trapezium (P: 0.24 +/- 0.04 vs T: 0.12 +/- 0.03, p<.05), serratus anterior (P: 0.42 +/- 0.11 vs T: 0.27 +/- 0.05, p<.05), and shoulder external rotator (P: 0.22 +/- 0.04 vs T: 0.18 +/- 0.02, p<.05). No significant difference was found in shoulder internal rotator between pitchers and tennis players. The primary finding of current study was that the healthy tennis players had weaker lower trapezium, and serratus anterior than pitchers.