A Study On Isometric Muscle Strength Characteristics Of Elbow And Knee Flexor-Extensor Muscle Groups In Outstanding Male

Objective: In this study,the isometric muscle strength testing system was used to perform isometric centripetal muscle strength tests on the elbow and knee joints of some active athletes of the Shanxi men’s weightlifting team to provide quantitative indices of the athletes’ elbow and knee joint movement ability and function.By analyzing the isokinetic muscle strength performance of the relevant muscle groups at different speeds and comparing them with the relevant results in the same type of studies,the strength quality characteristics and changes in the elbow and knee flexors and extensors of the central links of the upper and lower limbs of weightlifters at different exercise speeds were summarized to provide a reference basis for more targeted strength training and injury prevention for weightlifters,and to provide a reference for future research on this project.It also provides a reference for future research.Methods: In this paper,isometric muscle strength tests were performed on elbow joints(30°/s,5 times,180°/s,5 times)and knee joints(60°/s,5 times,180°/s,5 times)of seven active athletes of Shanxi male weightlifting team using CYBEX-Norm770 isometric muscle strength testing system.Excel and SPSS 26.0 data statistical software were used to count the test results and analyze the peak moment(PT),relative peak moment(PT/BW),flexor-extensor peak moment ratio,heterolateral homonymous muscle strength ratio and mean power(PW)in elbow and knee joints in fast(180°/s)and slow(30°/s,60°/s)modes in combination with weightliftingspecific characteristics and homologous studies.and other muscle functional parameters were characterized and changed.Results:(1)In the slow test(elbow: 30°/s,knee: 60°/s)in male weightlifters,the PT,PT/BW of bilateral elbow extensors and bilateral knee flexors and extensors were significantly greater than in the fast test(elbow and knee: 180°/s)(P<0.01),and the PT and PT/BW of the right elbow flexors were significantly smaller in the slow test than in the fast test(P<0.05).(2)The ratio of the peak flexion and extension moments(F/E)of both elbow joints was significantly greater in the fast test than in the slow test(P<0.01),and F/E ranged from 0.66 to 1.03.At a test speed of 30°/s,the right elbow F/E was only 0.66±0.17.The peak knee flexion-extension moment ratio(H/Q)was greater in the fast test than in the slow test,with the left knee H/Q showing a significant difference between the two tests(P<0.05).H/Q was small,ranging from0.53 to 0.63.(3)The heteronymous extensor ratio of the elbow and knee heteronymously in male weightlifters was greater than 10%,but smaller than 20%,which is in the suspect range.The knee heterolateral eponymous flexor muscle strength ratios were all less than 10%,which were within the normal range.(4)The average power of bilateral elbow and knee flexor and extensor muscle groups were significantly greater in the fast test than in the slow test for weightlifters(P<0.01).The AP of the right elbow flexors and extensors was significantly higher than that of the left side at a test speed of 180°/s(P<0.05).The AP of the right knee extensor was significantly higher than that of the left at the same test speed(P<0.05).Conclusions:(1)In the centripetal contraction mode,PT and PT/BW decrease with the increase of angular velocity,i.e.,the muscle contraction speed is inversely proportional to the force,which is consistent with the mechanical characteristics and physical properties of the muscle.(2)weightlifting athletes elbow and knee extensor muscle strength is better than flexion and extension,and weightlifting project technical movement characteristics are closely related.The right elbow and bilateral knee flexor and extensor muscle groups are unevenly developed,and the quality of flexor strength is weaker,which has a certain risk of injury.(3)Male weightlifters have more balanced knee flexor muscle strength bilaterally,but the difference in muscle strength between the right and left elbow and knee extensors is large,and the explosive strength of the right elbow and knee extensors is significantly better than that of the left,with potential injury risks.(4)The speed threshold of AP decline will be relatively shifted back in people with high training level,that is,the stronger the athletic ability,the stronger the explosive power of flexor and extensor muscle groups at high speed.The right elbow flexors and extensors and the right knee extensors had significantly better rapid strength than the left.