神经—肌肉疲劳前后运动鞋对落地冲击的下肢生物力学影响

发布时间：2018-03-11 02:18

本文选题：疲劳　切入点：落地　出处：《上海体育学院》2017年硕士论文　论文类型：学位论文

【摘要】：研究背景跑、跳运动中下肢所受的过度冲击被认为是造成运动损伤的原因之一。现代运动鞋的结构和材质理论上能够避免足部和下肢在跑、跳过程中承受过多的冲击力。然而,由于人体自身存在一定的适应和调节能力,进而使运动鞋的缓冲避震作用已不仅局限于单纯的力学效果。另外,长时间高强度的运动必然导致疲劳,而神经肌肉疲劳则会导致下肢肌-骨控制的改变,那么此时运动鞋的缓冲功能是否会更显著?因此本研究的目的是探讨疲劳状态下穿缓冲型/无缓冲运动鞋对落地动作下肢冲击力特征以及运动学和动力学的影响。研究方法选取上海体育学院15名篮球专项运动员(22.1±1.7岁,179.3±3.2厘米,72.2±5.5公斤),受试者按要求接受15×4米折返跑,接着完成连续5次纵跳为一组的运动干预,直到受试者纵跳高度无法达到其疲劳前最大纵跳高度的70%。使用10个Vicon红外高速摄像头(采样频率240Hz)和2块Kistler三维测力台(采样频率1200Hz)成功同步采集3次疲劳前后受试者穿不同缓冲性能的运动鞋从60cm高落下时的地面反作用力、运动学和动力学参数,并采用双因素重复测量方差分析对实验结果进行统计,显著性水平α设为0.05。研究结果1)不同运动鞋在疲劳前后对髋、膝、踝三关节矢状面运动学的影响穿不同缓冲性能的运动鞋在疲劳前后,在髋、膝、踝三关节的触地(最大)角度、最小角度以及到达时间和关节活动度方面均未发现有显著性的差异;另外在最大关节角速度上,仅发现疲劳前髋关节处,穿高缓冲运动鞋时角速度显著大于对照组,其他方面都没发现显著差异;2)不同运动鞋在疲劳前后对踝关节矢状面动力学的影响针对踝关节跖屈峰值力矩和关节刚度,我们发现疲劳前后穿着不同缓冲性能运动鞋时,踝关节跖屈力矩和关节刚度并没有发生显著性的改变,在到达峰值时间上也不存在显著性变化;3)不同运动鞋在疲劳前后对下肢所受垂直方向冲击力的影响针对冲击力和负载率我们发现,疲劳后穿着高缓冲鞋的后跟处冲击力峰值、负载率和前掌的负载率均显著小于对照组(p0.01),同时到达前掌冲击力峰值的时间也显著更长(p0.05);另外在疲劳前高缓冲鞋后跟处负载率也显著更小(p0.01)。研究结论在神经-肌肉疲劳前,运动鞋减震作用在落地冲击过程中并不突出;但当疲劳后,理论上神经肌骨系统控制在人体落地动作中的作用减弱,尽管在下肢生物力学特征(如运动学和动力学)本研究并未发现明显差异,但是穿着高缓冲鞋无论是在减小前掌或后跟的冲击力或是负载率的效果相比疲劳前更为显著。因此,运动鞋可以在人体神经—肌肉疲劳前为机体提供一定的冲击减震保护;但在疲劳后,人体下肢神经肌肉控制策略减弱时,运动鞋的缓冲保护作用更加显著进而可能有利于降低疲劳后落地冲击损伤的发生。
[Abstract]:Background running, the excessive impact on the lower limbs in jumping is considered to be one of the causes of sports injuries. The structure and material of modern sports shoes can theoretically avoid excessive impact on the foot and lower limbs during running and jumping. Because the human body has the ability to adapt and adjust itself, the cushioning and shock absorber of sports shoes is not only limited to the simple mechanical effect, but also the fatigue caused by the long time and high intensity exercise. But the neuromuscular fatigue will lead to lower limb muscle-bone control changes, then the sneaker buffering function will be more significant? Therefore, the purpose of this study is to explore the effects of wearing cushioning / non-cushioning sneakers on the impact force characteristics, kinematics and dynamics of the lower extremity of landing movement under fatigue. The research method is to select 15 basketball players from Shanghai Institute of physical Education. The athletes were 22.1 卤1.7 years old and 179.3 卤3.2 cm / 72.2 卤5.5 kg / kg respectively. The subjects accepted the 15 脳 4 meter reentry race as required. And then completed five consecutive longitudinal jumps into a group of exercise intervention, The maximum vertical jump height of the subjects before fatigue was not up to 70. Ten Vicon infrared high-speed cameras (sampling frequency 240 Hz) and two Kistler 3D force measuring stations (sampling frequency 1 200 Hz) were successfully used to synchronize the acquisition of 3 times before and after fatigue. The subjects wore sneakers with different cushioning properties to react on the ground when they fell from a height of 60 cm. The parameters of kinematics and dynamics were analyzed by means of double factor repeated analysis of variance. The significant level of 伪 was set to 0.05. The results showed that 1) the hip and knee of different sneakers were compared before and after fatigue. The effect of sagittal kinematics on ankle triangulation: wear sneakers with different cushioning properties before and after fatigue, touching the ground (maximum) angle of the hip, knee, and ankle joints before and after fatigue, There was no significant difference in the minimum angle, the time of arrival and the joint motion. In addition, on the maximum joint angular velocity, only the hip joint before fatigue was found, and the angular velocity of high cushioning sneaker was significantly higher than that of the control group. No significant difference was found in other aspects. (2) the effect of different sports shoes on the sagittal dynamics of ankle joint before and after fatigue. The peak moment of metatarsal flexion and stiffness of ankle joint were studied. We found that when wearing sneakers with different cushioning performance before and after fatigue, There were no significant changes in the ankle metatarsal flexion torque and joint stiffness. There is no significant change in the time of reaching the peak value. (3) the influence of different sneakers on the perpendicular impact force of lower extremities before and after fatigue. We found that the peak impact force at the heel of high cushioning shoes after fatigue was found to be due to the impact force and load rate. The load rate and the load rate of the front palms were significantly lower than those of the control group, and the time to reach the peak impact force of the front palms was significantly longer than that of the control group, and the load rate at the heel of the high cushioning shoes before fatigue was also significantly smaller than that of the control group. The shock absorption effect of sports shoes is not prominent in the course of landing impact; but after fatigue, the function of neural muscle and bone system control in the human body landing action is weakened theoretically. Although there is no significant difference in lower limb biomechanical characteristics (such as kinematics and dynamics), wearing high cushioning shoes is more effective than fatigue in reducing the impact force or load rate of the front soles or heels. Sports shoes can provide certain shock absorber protection for human body before nerve-muscle fatigue, but after fatigue, the neuromuscular control strategy of human lower extremity is weakened. The cushioning effect of sports shoes is more significant, which may help to reduce the occurrence of landing impact damage after fatigue.
【学位授予单位】：上海体育学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：G804.6

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