The analysis of balance in baseball pitchers and javelin throwers

• Main Authors: Jen-Hao Cheng, 鄭人豪
• Other Authors: Wei-Hsiu Lin
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/48348536488038947411

碩士 === 國立嘉義大學 === 體育與健康休閒研究所 === 99 === The purpose of this study was to investigate the static and dynamic balance in baseball pitchers and javelin throwers through three balance evaluation methods. 24 university male students were recruited in this study [12 college baseball pitchers (Age: 20.0±1.3; Height: 177.8±6.2; Weight: 77.5±8.2) and 12 college javelin throwers (Age: 21.4±2.0; Height: 180.2±5.8; Weight: 89.4±14.7) ]. The athletic single leg stability testing mode of the Biodex Balance System (BBS) was used to evaluate the dynamic (level 6) and static balance (level 12) and the Medial-lateral stability index (MLSI), Anterior-posterior stability index (APSI) and an Overall stability index (OSI) were measured. Also, the average radius, velocity and area of the center-of-pressure (COP) was measured using AMTI AccuSway force plate to evaluate the static balance in single-leg standing with eye-opened and eye-closed conditions. Simplified star excursion balance test (SEBT) was used to measure the subjects’ dynamic balance, and normalized reach distance in three directions were collected. The paired t-test was used to compare all the variables between trail leg and stride leg of baseball pitchers, propulsive leg and braking leg of javelin throwers. The independent t-test was used to compare trail leg of baseball pitchers with propulsive leg of javelin throwers and stride leg of baseball pitchers with braking leg of javelin throwers. Results: The APSI of level 6 and the normalized reach distance in posterolateral direction of the trail leg were significant better than the stride leg. No significant difference was found between the propulsive leg and braking leg in all the variables. The average radius and area of the COP during single-leg standing with eyes-opened conditions of the propulsive leg were better than the trail leg. It is concluded that both the baseball pitchers and javelin throwers demonstrate specific characteristics in balance control. There are no difference between the propulsive leg and braking leg of javelin throwers in dynamic and static balance performance. However, the dynamic balance performance of the trail leg is significantly better than the stride leg in baseball pitchers. The static balance performance of the propulsive leg of javelin throwers is also better than the trail leg of the baseball pitchers. The cause of these differences requires further study.