The Effect Of Hand Support On The Flexion And Extensor Moment Characteristics Of Knee Joints In Nordic Post-shoulder Muscle Training

Objective:In sporting events,many projects require athletes to perform frequent and fast movements.In this process,the knee joint needs to perform repeated flexion and extension exercises,which plays a crucial role.However,the imbalance of muscle strength before and after the knee tends to cause damage to the posterior muscles.In this study,the new Nordic hamstring exercise was used abroad to test the flexion and extensor muscle moment characteristics of knee joints with isokinetic muscle strength,and to explore the training of two different Nordic posterior muscle groups with hand support and non-hand support.The flexion and extensor strength characteristics of the method,carefully studying the different training effects corresponding to different training methods,better improving the training methods and means,enhancing the timeliness and pertinence of strength training,achieving specific training purposes,and better increasing the number of shares The strength of muscle groups can better prevent the damage of the back muscles.Subject:Thirty-two students(male)from Shandong Normal University were selected as subjects.All subjects had no lower limb sports injuries and other diseases that restricted upper and lower extremities.There were no posterior strand muscle injuries,and the knee range was greater than 90 °.In good health,all subjects are required not to perform intense exercise the day before the experiment to reduce the effects of sports injuries and muscle fatigue on the experiment.Methods:Twenty-two subjects were enrolled and randomized into two groups.One group consisted of 16 non-hand support groups(group A)and the remaining 16 were hand support groups(group B).The experimental period was 8 weeks and 3 Nordic posterior muscle exercises were performed weekly.Training load of 15 times / group× 6 groups,each interval of 3min.Before and after training intervention,the kinetic parameters of knee flexors and extensors were measured using the isokinetic force test system.The results were statistically analyzed and the effects of different forms of Nordic limbs muscle training on flexors and extensors of knee flexors were compared.Result:1.8 weeks of training,there was no significant difference in extensor to centripetal moment after hand-training and non-hand-support groups,and flexor to centripetal moment increased,Compared with a very significant difference(P <0.01).2.8 weeks of training,flexion and extension flexors and flexors of knee flexion and flexion groups both increased after peak training,but there was a significant difference between the two groups(P <0.05)).3.8 weeks of training,the flexion-extension ratio of both groups increased under eccentric and centripetal test,and the value of non-hand support group increased significantly(P <0.05).Analysis conclusion:1.Two groups of training methods can improve the muscle strength of the posterior femoral muscles,non-hand support group training effect is more significant.2.The two training methods can improve the ratio of knee flexors and extensors,balance the anterior and posterior knee muscles,is conducive to the prevention of sports injury.3.Two sets of training methods should be selected according to the actual situation of the athletes in practical application.