不同着地冲击模式的下肢生物力学研究
The Biomechanics of Lower Limb during Active Landing and Passive Landing
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摘要: 目的:比较主动和被动两种不同着地模式下,下肢运动学、冲击力特征、软组织振动和肌肉活化模式,以及全面理解人体下肢着地冲击的神经-肌骨系统调控机制。方法:选取12名体育教育专业篮球专项男性运动员,受试者随机进行3种下落高度(30cm、45cm、60cm)×两种下落方式的测试,每组测试重复3次。主要选择运动学、冲击力、软组织振动以及肌电图学相关参数进行分析。结果:3种高度条件下的触地瞬间和缓冲期,主动着地相比于被动着地,髋关节和膝关节的关节角度显著减小(P<0.05),角速度明显增大(P<0.05)。3种高度条件下,主动着地的冲击力峰值(P<0.05)、最大负载率(P<0.05)、冲击力频率(P<0.05)均显著小于被动着地。股四头肌(除60cm)和腘绳肌在3种高度情况下,主动着地的加速度最大振幅均显著小于被动着地(P<0.01)。股四头肌和腘绳肌的软组织阻尼在3种高度情况下,主动着地均显著大于被动着地(P<0.05)。在触地前激活、触地后激活和缓冲阶段,主动着地部分肌肉的肌电振幅均显著大于被动着地(P<0.05)。结论:主动着地情况下,人体可以通过积极调整肌骨系统的落地策略,有效减少冲击传递下的软组织振动,进而达到有效完成动作控制和降低运动损伤风险的作用。相反,被动着地时,肌骨系统需要承受更大的冲击力和相应软组织的振动,进一步增加了冲击损伤的危险。Abstract: Objective:To examine the kinematics,impact force,tissue vibration and muscle activity during active landing(AL)and passive landing(PL).In addition,the aim was to understand the regulation mechanism of nerves-muscle skeletal system during landing.Methods:Twelve trained basketball male volunteers in physical education were required to complete three different attitudes(30cm、45cm、60cm)×two different landing models(AL & PL).The variables were measured including kinematic of lower extremity,impact characteristics,soft tissue acceleration signal and EMG signals.Results:At three different attitudes,AL showed significantly decrease the knee and hip joint angle(P<0.05),and significantly increase angle velocity(P<0.05)during the instantaneous moment of touchdown and cushion phase compared with PL.The peak of impact force(P<0.05),maximum loading rate(P<0.05)and impact frequency(P<0.05)were significantly reduce during AL compared with PL at three different attitudes.AL showed significantly decrease the maximum amplitude of accelerate of quadriceps femoris(except 60cm)(P<0.01)and hamstrings(P<0.01)at three different attitudes compared with PL.At three different attitudes,AL showed significantly increase the tissue damping(P<0.05)compared with PL.The parts of muscles showed significant increase the EMG amplitude(P<0.05)during AL in per-activation,post-activation and cushion phase compared with PL.Conclusion:At the case of AL,the human being can adjustment the landing strategy of muscle-skeletal system,which mean effective decrease the tissue vibrate under the impact force.Eventually,the effective motor control were resulted in decrease the risk of sports injuries.On the counter,muscle-skeletal system were bear higher impact force and tissue vibrate,and improve the risk of sports injuries.