静态拉伸训练不同阶段对男性排球运动员踝关节动力学及下肢缓冲特征的影响

目的:测试静态拉伸训练前、后男性青年排球运动员踝关节跖-背屈动作和落地缓冲动作生物力学参数,分析静态拉伸对踝关节动力学及下肢缓冲特征影响的机制及意义。方法:22名健康男性青年高水平排球运动员随机分为实验组和对照组,对实验组进行36组下肢静态拉伸训练。分别于训练前、12组训练后、24组训练后、36组训练后、停训4周恢复期后测试踝关节跖-背屈动力学和缓冲期下肢及下肢各关节动力学、运动学数据,同步测试小腿后肌群影像学。结果:12组训练后至恢复期踝关节跖-背屈范围增加非常显著(P<0.01),小腿后肌群被动刚度显著降低(P<0.05),二者的增加/降低率%于36组训练后改变最明显(P<0.05),且变化率%之间呈非常显著正相关(P<0.01)。训练后小腿后肌群滞后%明显降低(P<0.05),肌腱弹性回缩率%明显升高(P<0.05),且二者之间呈显著负相关(P<0.05)。下肢刚度显著降低(P<0.05),髋、膝、踝关节做功均显著增加(P<0.05),训练各阶段踝关节做功贡献度均最大(P<0.05)。结论:静态拉伸训练早期即可通过降低肌肉-肌腱复合体被动刚度而增加关节活动范围和通过降低滞后而提高肌腱弹性回缩率并保持至恢复期,提示,静态拉伸训练急性期和慢性期均能提高肌肉-肌腱复合体的柔韧性及肌腱的弹性能利用率,从而有利于提高拉长-缩短周期运动表现。训练后各阶段下肢刚度降低的同时各关节缓冲吸能增加且踝关节是吸能的主要部位,提示,静态拉伸可通过调整缓冲模式、提高关节能量吸收、增效踝关节作用降低排球运动员下肢损伤的风险。

Effects of Different Phases of Static Stretch Training on Ankle Dynamics and Lower Limb Cushioning Properties in Male Volleyball Athletes

Objective:To investigate the effects and mechanisms of static stretch training on ankle dynamics and lower limb cushioning properties by measuring the biomechanical parameters of ankle and lower limb during flex-dorsiflexing and cushioning phase after landing before and after static stretch training in male volleyball athletes.Methods:22 male health young elite volleyball athletes were randomly divided into training and control group.Lower limb static stretch training was conducted in training group for 36 sessions,and the ankle flex-dorsiflexion dynamics,calf muscle imaging,lower limb and its joints kinematics and dynamics during cushioning phase were measured at before training,after 12,24 and 36 training sessions and after 4 weeks recovery,respectively.Results:The flex-dorsiflex range of motion was increased from 12 training sessions to recovery period(P<0.01),and the calf muscle’s passive stiffness was significantly decreased(P<0.05).Both of the changes of increase/decrease rate were significant after 36 sessions(P<0.05),and a positive correlation was observed between their change rate(P<0.05).After training,the hysteresis was significantly decreased(P<0.05),but the tendon elastic recoil rate was significantly increased(P<0.05),a negative correlation was observed between them(P<0.05).In addition,the leg stiffness were significantly decreased after training(P<0.05),but the joints work of hip,knee,ankle were all increased(P<0.05).The contribution of ankle work was greatest in all training periods(P<0.05).Conclusion:In the early phase of static stretch training,the ankle range of motion was significantly enlarged through decreasing the passive stiffness,and tendon elastic recoil rate was significantly promoted through decreasing hysteresis,which sustained to retention period.It was suggested that the stretch-shortening cycle performance can be elevated through increasing flexibility of muscle-tendon complex and increasing elastic energy utilization of tendon.The lower limb stiffness was decreased and joints’energy absorption were increased,and at the same time the ankle energy absorption was the greatest during different phases after training,which suggesting that the static stretching can impair the lower limb injury risk through modulating lower limb cushioning pattern,promoting joint energy absorption,reinforcing ankle function in volleyball athletes.