Analysis of the Lower Limb Muscles' Function for the Prevention of KNEE JOINT INJURIES of the Intramural Baseball Pitchers of Colleges and Universities

Abstract

Purpose: The purpose of this analysis is to provide the basic data for the prevention of knee joint damages by analyzing differences in the isokinetic muscular function of knee joints as per the pitching speed of 21 intramu-ral baseball players of colleges and universities. Method: The subjects of this study were 21 intramural baseball players of colleges and universities, whose length of experiences were 2 to 7 years. By measuring the pitching speed, they were classified as S1 group whose maximum ball speed was 110km/h or greater, S2 group whose maximum ball speed was less than 110km/h to 100km/h or greater, and S3 group whose maximum ball speed was less than 100km/h, respectively. The isokinetic muscular strength of knee joints was measured for all of the 3 groups, and the strength of the left and right flexors and extensors were measured at 60°, 180°, and 240°, respectively. The data processing for this study was performed by using the SPSS 18.0 statistical program to calculate the mean and standard deviation for each of the items, and the one-way ANOVA was performed to compare the differences for each item by group, while using the Tukey method as an ex post analysis between the groups. Furthermore, the multiple linear regression was performed to identify the influence of the isokinetic muscular function of knee joints according to the angular speed on the pitching speed. The statistical significance level was set to p<.05, respec-tively. Results: The results of measuring the isokinetic muscular strength of knee joints are as follows. As for the PT and WPR measured at an angular speed of 60°, the S1 group turned out to be significantly higher(p<.05) in the left flexors and extensors than S3 group. As for the PT and WPR measured at an angular speed of 180°, the S1 and S2 groups turned out to be significantly higher(p<.05) in the left extensors than the S3 group. As for the PT measured at an angular speed of 240°, S1 and S2 groups in the left extensor turned out to be significantly high-er(p<.05) than S3 group. As for the WPR, S1 group turned out to be significantly(p<.05) higher than S3 group. The results of performing the multiple linear regression are as follows with a view to discover the effect of iso-kinetic muscular strength of knee joints on the pitching speed. At the angular speeds of 180° and 240°, the regression segments of the left knee joint extensors for both the PT and WPR turned out to have a significant ef-fect at the 5% level. R2, which is the explanatory power of the regression model which explains changes in the pitching speed for the left knee joint extensors, turned out to have an explanatory power in the range of 37.9-55.5%, respectively. Conclusion: Gathering the results above, it turned out that the higher the pitching speed for the group, the superior the muscular function, and in particular, the extensors on the left side demonstrated such remarkably pronounced characteristics. Such results suggest that the extensor muscles could influence the pitching speed for the stretching motion(acceleration) of the left legs during the pitching. Furthermore, in order to prevent injuries, attention ought to be paid to strengthening the counter muscular of the muscles which are primarily used.