摘要
目的:比较分析不同起跑器抵脚板水平旋转角度对运动员起跑蹬伸力的影响。方法:以大学高水平男子短跑运动员为实验对象,将改造的抵脚板分别安装于两台三维测力平台上。实验对象按照个人习惯对起跑器长度和倾斜度进行调节设置,设置完成后不做改变。实验只对起跑器水平旋转角度进行控制,共设定4种条件:1)两支抵脚板均外旋0°;2)两支抵脚板均外旋2.5°;3)两支抵脚板均外旋5°;4)运动员根据前3种抵脚板外旋角度的主观体验,对两支抵脚板转角分别进行个性化调整。通过测力平台对4种实验条件下运动员起跑前、后脚蹬伸力幅值和时间特征进行记录。结论:1)带有旋转角度的前抵脚板在X、Y和Z方向均增加了起跑蹬伸力峰值,尤其在X方向更为显著;虽然后抵脚板在X方向减小蹬伸力峰值,但其增加了Y和Z方向蹬伸力峰值,尤其是最佳转角在Y方向增加10%的向前推力;2)2.5°转角几乎没有改变前、后脚蹬伸力出现时相,但5°和最佳转角改变了蹬伸力峰值出现时相;3)5°转角显著性地缩短蹬离时间0.0166s,最佳转角缩短蹬离时间0.0063s;4)带有旋转角度的抵脚板有利于运动员起跑后第一步侧向蹬伸,减少蹬伸侧滑现象。建议未来起跑器改进与优化应重点考虑抵脚板水平旋转角度因素。
Objective： The pilot study was conducted to examine the effects of starting blocks with horizontal rotational angle （blocks with HRA） on sprinters, the main purpose is to pro- vide theoretical and experimental data for designing and optimization of starting blocks. Meth- ods： College sprinters were recruited as subjects and starting blocks redesigned was fixed on two force plates in separately. Subjects adjusted the width and length of two blocks according to their own habits. We chose the horizontal angle of blocks as independent variable which has 4 levels ： 1 ） 2 blocks were rotated for 0~ ~ 2） 2 blocks were rotated for 2.5 o ~ 3 ） 2 blocks were rotated for 5~~4） 2 blocks were rotated according to their own subjective experience （subjec- tive angle）. 2 force plates were used to record the force exerted by forefoot and hindfoot during sprint starting. Conclusion ： 1） the blocks with HRA increased significantly the pushoff force of forefoot and decreased the force of hindfoot at X direction. And it increased the force on the forefoot and hindfoot at Y and Z direction, especially, subjective angle increased the force on hindfoot at Y direction by 10 %. 2 ） 2. 5 almostly didn ~ t change the time phase, but 5~ and subjective HRA changed the corresponding time phase. 3） 5~HRA sharply shortened the push- off time by 0. 0166s and subjective HRA by 0. 0063s. 4） It is advantageous for sprinters to start their first step from block with HRA to side direction, may lower the probability of slip- ping from block. It suggests that HRA should be considered for designing and improving the next generation of the starting blocks.
出处
《中国体育科技》
CSSCI
北大核心
2014年第1期23-28,135,共7页
China Sport Science and Technology
基金
中央高校基本科研业务费专项资金(DUT10RW3057)
关键词
起跑器
旋转角度
测力平台
蹬伸力
starting blocks rotational angle force plates pushoff force
