The Effect of Trunk Extension Strengthening Exercise on Muscle Performance of Upper Limb in Adolescent Baseball Player

체간 신전근 강화훈련이 청소년기 야구선수의 상지 근수행력에 미치는 영향

The purpose of this dissertation was to analyze the effect of trunk extension strengthening exercise on muscle performance of the upper limb in adolescent baseball player. The twenty people were studied : experimental group(10), comparative group(10). The experimental group has done trunk extension strengthening exercise for 8 weeks. The study analyzes isometric maximal strength of shoulder internal rotation. shoulder external rotation, elbow flexion, elbow extension, forearm pronation, forearm supination and ball speed. All of subjects were tested for 3 times ; pre, mid, post. The results were as follows; 1. Maximal isometric strength of upper limb, during trunk extension strengthening exercise in experimental group, shoulder internal rotation and external rotation showed it has slightly increased and comparative group showed it has no change, but not significant elbow flexion and extension significantly(p<0.05) increased after exercise either for 4 or 8 weeks compared with that of control group. Forearm pronation showed not significantly changed in both group, but significantly different between group either for 4 or 8 weeks. Forearm supination, significantly((p<0.05) increased after 8 weeks in experimental group. 2. Ball speed showed slightly increased but not significantly in experimental group. These results it may expect improvement of upper limb muscle performance of upper limb in adolescent baseball player. However, in case of shoulder a point of view of bunk extension strengthening exercise of this study hasn't a significant influence. More experimental studies are needs, hereafter which will use more experimental subjects and various methods of exercise and new application of treatment term to define significant change.