The research of lower extremity stiffness and linear acceleration performance in team sports athletes

• Main Authors: YAO XIANG, 姚翔
• Other Authors: CHIANG, CHIEG-YING
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/q5rbgs

碩士 === 國立體育大學 === 競技與教練科學研究所 === 106 === Purpose: To understand in team sports, better athletes have what kinds of acceleration characteristics. To also investigate the relationships between lower extremity stiffness and key acceleration characteristics during 10m sprint phase in a population of collegiate Division I men’s basketball players. Methods: 15 collegiate Division I men’s basketball players (height 183.4±7.6cm, weight 81.9±15.6kg), for 0-10m sprint, using time gate and high speed camera to collect sprint time and acceleration characteristics. For lower extremity stiffness in jump tasks, force plate and high speed camera were used to collect force and movements. Pearson product-moment correlation coefficients (r) were performed on all measures to identify whether any significant relationships were present between the lower extremity stiffness and acceleration characteristics. Independent-Samples t Test was used to compare differences between faster and slower group. Result: 0-10m sprint time have significantly negative correlation with 0-5m step length and frequency (r = -.77, p < .001; r = -.70, p <.001). 0-5m sprint time have significantly negative correlation with 0-5m step length and frequency (r = -.66, p < .01; r = -.79, p <.001). 5-10m sprint time have significantly negative correlation with 0-5m step length (r = -.60, p < .01). Vertical stiffness of countermovement jump have medium negative correlation with 0-5 ground contact time (r = -.39, p < .05). Vertical stiffness of hopping and ankle stiffness of drop jump have medium to high correlation with 0-5m and 5-10m ground contact time (r = -.60, p < .01; r = -.62, p <.01; r = -.34, p <.05; r = -.36, p <.05). Vertical stiffness of drop jump have medium to high correlation with 0-5m step frequency (r = .45, p < .05). Faster groups with better 10m sprint have significant differences compare to slower group (p< .05), but no differences in lower extremity stiffness. Conclusion: In the future, when coaches are planning acceleration trainings, the main goal in 0-5m should focus on having longer step length, faster step frequency and shorter ground contact time. After 5m, when step frequency maintain stable, producing longer step length should be the main goal. On the other hand, using vertical stiffness of countermovement jump and hopping test and ankle stiffness of drop jump can be used for coaches to monitor improvements of ground contact time in early acceleration phase. Vertical stiffness of drop jump can be the way to monitor step frequency in 0-5m sprint.