The Effect Of Different Knee Joint Angles And Contraction Methods On The Flexion And Extension Ratio Of The Muscles Before And After The Thigh

Objective:The knee joint is the largest and most complex and easily injured joint. This paper, through different knee angles and different motion modes, affects the ratio of flexion and extension to the knee joint. The purpose of the study is to explore the influence of different knee angles and the form of motion on the stability of the knee joint.Methods:On 25 males and 25 females were about on both sides of the isometric testing,isokinetic concentric and isokinetic eccentric test. By using the German con-trex isokinetic measurement system of young men and women on both sides of the knee joint were isometric and isokinetic concentric isokinetic eccentric test and on the maximum torque value of collection. Analysis of the relationship between the different angles and different forms of motion and the ratio of the anterior and posterior muscle groups.Results:1, the length of the test male dominant leg knee H/Q value range is 40%-100%.Isometric testing of male non dominant leg knee joint H/Q values range is 40%-95%.The value of H/Q decreases with the increase of the angle, the maximum of H/Q is30°, and the minimum of H/Q is at 90°. Isometric testing of female dominant leg H/Q range is 40%-75%. H/Q with the angle of the increase in the value of H/Q is smaller, H/Q at 30°, the maximum. Isometric testing of female non dominant leg H/Q value range 35%-75%. Maximum value of H/Q at 30°.2, as long as the value of H/Q of the male and female dominant leg, the difference is very significant(P < 0.01), and the value of H/Q < 40) is higher than that of female.The values of H/Q of the non dominant leg knee joint of the men and women of the same length were significantly different(P < 0.014) at 40°, 50°, 60°, and the difference between men and women was very significant(P < 0.01), and the value of H/Q in male was higher than that in female.3, the value of H/Q of the knee joint with constant velocity increased with the increase of the angular velocity. There was no significant difference in the value of 60 degree/s between the dominant and non dominant leg H/Q of the dominant leg of a constant velocity. The other angular velocities were not significantly different, and the values of H/Q in the female dominant and non dominant leg joints were higher than those in the male. Dominant leg male and female H/Q value of 120 ° /s difference was significant, angular velocity 60°/s(P > 0.057), 180°/s(P > 0.056) the difference was not significant. Male and female non dominant leg H/Q value of 240 ° /s significant difference(P < 0.05), other angular velocity difference is not significant.4, In the dynamic process of constant velocity test of 180 degrees 30~40, the knee joint angle of /s degrees, the strength ratio of the anterior and posterior muscles of the knee is the largest, the knee angle at 70°is the lowest flexion and extension torque ratio.5, The value of H/Q in the constant velocity centrifuge test in 56%-74%, the difference of the dominant leg between the angular velocity of H/Q is not significant(P > 0.05). In addition, the difference of H/Q between different angular velocity of non dominant leg was not significant(P > 0.05).Conclusion:1, as long as the test, the knee angle is bigger, the ratio of flexor and extensor torque is small. 30°maximum, minimum 90°. Women than men with knee H/Q is smaller.Female non dominant leg knee H/Q value than the dominant leg H/Q is low, the angle is too large or too small are more likely to cause injury.2, There were significant differences in the values of the dominant and non dominant leg H/Q of the knee joint in different angles.3, the value of H/Q of the knee joint with constant velocity increased with the increase of the angular velocity, the faster the value of the angular velocity, the greater the value of H/Q. When the angular velocity is 60°/s, there is a significant difference between the active leg and the non active leg. The value difference of the same angular velocity H/Q between men and women is not significant.4. In addition to the 120°/s of the centrifugal test in addition to the male dominant leg H/Q difference was more significant than other angular velocity between the dominant and non dominant legs and between the different angular velocities of the legs were not significantly different.5, in the angular velocity for 180 deg / sec during isokinetic centripetal exercise and60°and 70°H / Q value than other smaller angle, the reason is due to 60°and 70°hamstring muscle strength compared with femoral quadriceps strength is weak, in the testing process occurred injury risk than other angles greater.