The Effect of Game Participation by a Professional Pitcher on Isokinetic and Isometric Muscle

This study was conducted to identify the isokinetic muscular strength during the season in professional baseball pitchers. By medical and clinical tests of medical specialist (doctor), 21 players were selected for this study. Total results of 21 players were used as data. All variables were measured in pre-season, in-season, and post-season. Isokinetic and isometric muscle strength was measured by CSMi (Humac Co., U.S.A). Repeated measure MANOVA was used to verify differences between the groups. LSD (Least Significant Difference) was carried out when significant difference is appeared among times and independent T-test was used to analyze significant differences between groups. Significant level was p<.05. The results of this study were as follows: In isokinetic muscle strength test, ER/IR ratio of dominant shoulder was significantly lower than in non-dominant. Peak muscle strength (180°/sec) in dominant was significantly lower. In isometric muscle strength test, isometric - 25° ER muscle strength in dominant was significantly lower than in non-dominant. In conclusion, Isometric muscle strength of external rotators in dominant was lower and also decreased during the season. Therefore, further researches will be necessary for identifying effects of pitching on muscle strength in baseball players. Keywords: Component, Formatting, Isometric Muscle Strength, Isokinetic Muscle Strength, Baseball Player