腰伸肌群疲劳对上肢鞭打运动链活动特征的影响

The Effect of Lumbar Extensor Muscles Fatigue on the Upper Limb Whiplash Kinematic Chain

目的:探讨在上肢鞭打运动中,腰伸肌群疲劳对人体上肢鞭打运动链活动特征的影响。方法:以16名男羽毛球运动员(年龄19~26岁)为测试对象,收集受试者在腰伸肌群疲劳前、后原地杀球动作中,躯干及上肢各环节活动顺序及环节间相对活动节奏等运动学及肌电指标,并进行疲劳前后的比较分析。结果:腰伸肌群疲劳前后主要肌肉的激活顺序基本一致,表现出先躯干肌肉后上肢肌肉的顺序;髋、肩、肘、腕四关节峰值线速度出现的顺序在腰伸肌群疲劳前后一致,为髋-肘-肩-腕;肩关节相对于腕关节(P<0.05)、肘关节相对于腕关节(P<0.05)达到峰值线速度的时间差在腰伸肌群疲劳后相比于疲劳前明显增加;腰伸肌群疲劳后三角肌前束(P<0.05)、左侧竖脊肌(P<0.01)、左侧背阔肌(P<0.01)在挥拍击球阶段的肌肉激活时长明显增加,左侧腹内斜肌(P<0.05)激活时长明显减少。结论:1.腰伸肌群疲劳影响了上肢鞭打动作环节间的相对运动节奏,造成"动作脱节"现象,削弱了环节间动量矩的传递效率。2.由于腰伸肌群疲劳这一运动链弱势环节的存在,打破了上肢鞭打技术原有的动力定型,引起其他环节活动节奏的改变,体现了人体运动链各环节间相互影响的"补偿"特性。3.生理学层面,运动链环节间相对运动节奏改变的本质原因是局部肌肉疲劳使周围环节的神经-肌肉协调控制改变。

Objective To explore the effect of the lumbar extensor fatigue on the upper limb whiplash motion chain. Methods Sixteen male badminton players(aged 19~26 years) were selected, and their kinematic and electromyography indicators,such as the sequence of actions of the trunk and upper limbs and the relative action rhythm between the links,were collected during the upper limb whiplash before and after the fatigue of the lumber extensor muscles. Results The activation order of 16 main muscles during the upper limb whiplash were basically the same before and after the fatigue.The peak linear velocity of the hip appeared first,followed by that of the elbow,shoulder and wrist,which was of the same order before and after the fatigue of lumbar extensors. The time gap between the shoulder and wrist(P<0.05) as well as the elbow and wrist(P<0.05) to reach the peak linear velocity increased significantly after the fatigue of lumbar extensors. After the lumbar extensor fatigue,during the swing stroke,a significant increase was observed in the muscle activation of the anterior fasciculus deltoideus,the left erector spine,and the left lats(P<0.05,P<0.01 and P<0.01),but a significant decrease in the activation time of the left internal oblique(P<0.05). Conclusion The lumbar extensor fatigue disturbs the relative movement rhythm in the whipping movements of the upper limbs,resulting in"movement disconnection"and weakening the transfer efficiency of momentum in the links.The existence of lumbar extensor fatigue,the "weak link" of the motion chain,breaks the original dynamic stereotype of the upper limb whipping technology,and causes the change of the activity rhythm of other links,which reflects the "compensation" characteristics of the mutual influence of each link of the human movement chain. At the physiological level,such change is caused by the change of the coordinated control of the muscle in the peripheral link resulting from the local muscle fatigue.