A Study On The Effect Of Hamstring Contraction To Different Degrees Of Fatigue On Knee Joint Proprioception

Objective: Previous studies have shown that fatigue will increase the risk of musculoskeletal injury in the later stage of sports activities and competitions.However,with the change of the degree of fatigue,there are few studies on the changes of proprioceptive sensation.The purpose of this paper is to analyze the changes of muscle force and position sensation of knee joint under mild hamstring fatigue and hamstring severe fatigue,so as to find out the general rule of hamstring muscle proprioception affected by different degree of hamstring fatigue.The purpose of this study is to provide a theoretical basis for knee joint proprioceptive training and how to prevent injury in the future.This paper also analyzes the proprioceptive sensation index of hamstring muscle before and after fatigue and the muscle strength and joint position sensation of hamstring muscle before and after fatigue under different modes of constant velocity movement.the position sensation,muscle force sensation and hamstring muscle strength of hamstring muscle before and after fatigue were analyzed to further explain how the proprioceptive sensation of knee joint changed after hamstring fatigue.Methods: This paper mainly adopts the experimental method,taking 16 healthy young men as the experimental object,taking the effect of hamstring contraction to different degrees of fatigue on the ontological sensation of knee joint as the research object,using ISOMED2000 isokinetic muscle strength tester(Germany)to test the maximum isometric muscle strength(MVIC)of hamstring muscle,muscle force and knee joint position sensation before and after fatigue.The maximum peak torque of hamstring muscle under centripetal and eccentric movement without fatigue was measured.Results :(1)There were significant differences in absolute error and variable error of 30 °position perception of popliteal rope muscle after mild fatigue,constant error and variable error of 30 °position perception of hamstring muscle after moderate fatigue,and relative constant error of muscle force perception of popliteal cord muscle after severe fatigue.And the error of 30 °position perception constant after severe fatigue was statistically significant.Muscle strength sensation was statistically significant in both mild and moderate fatigue.There was no statistical significance in the 60 °position sensation of hamstring muscle before and after fatigue.(2)Before and after mild fatigue of hamstring muscle,there was a moderate correlation between the variable error of muscle force and 30 °position perception and the variable error of position perception.There was a moderate correlation between the relative constant error of muscle force sensation and the variable error of position sensation after moderate fatigue of hamstring muscle.there was no statistical significance in all the indexes of muscle force and position sensation of hamstring muscle before and after severe fatigue.(3)There was a negative correlation between the relative variable error and constant error of muscle force sensation and 60 °position sensation during mild fatigue of hamstring muscle.There is a moderate correlation between the relative constant error of muscle force perception and the variable error of position perception during moderate hamstring fatigue,and there is a moderate correlation between the relative absolute error of muscle force perception and the variable error of position perception.There is a moderate correlation between the relative absolute error of muscle force perception and the constant error of position perception in severe hamstring fatigue.However,all the indexes of muscle force and position sensation before hamstring fatigue were not statistically significant under the three degrees of hamstring fatigue.(4)In the correlation analysis between force perception index and muscle strength characteristics of hamstring muscle under mild fatigue,there was a moderate correlation between the relative variable error of muscle force perception and the relative peak torque of isokinetic centripetal motion mode.the relative variable error of hamstring muscle force perception under moderate fatigue was negatively correlated with the relative peak torque of eccentric motion mode.In severe hamstring fatigue,there was no correlation between all force sensation indexes and isokinetic muscle force centripetal force,and there was no correlation between the relative peak torque in eccentric exercise mode.Only when the position sensation of the knee joint is 60 °,there is a low negative correlation between the absolute error and the relative peak moment of the centripetal motion mode.There was no correlation between all indexes and isokinetic muscle force centripetal and eccentric movement mode relative peak torque of hamstring muscle in moderate and severe fatigue.Conclusion:(1)In this paper,we measured the ICC coefficient before and after knee hamstring fatigue and found that the constant error,absolute error and variable error of the assessment of muscle force perception and joint position perception were reliable.(2)After severe hamstring fatigue,the proprioception-muscle sensation of the knee decreases.When the hamstring is severely fatigued,the degree of decrease in muscle strength is higher than before fatigue.(3)The 30 °knee extension position sensation of hamstring muscle decreased with the increase of fatigue degree before and after different fatigue,but the decrease of hamstring muscle after severe fatigue was less than that after moderate fatigue.The hamstring muscle fatigue had no effect on the joint position sensation of 60 °knee flexion.(4)Before and after hamstring fatigue,there was no high correlation between the indicators of muscle force and the indicators of joint position.There was no correlation between muscle strength before and after hamstring fatigue and knee extension at 30°.