Changes Characteristics In The Internal Force Of The Joints And The Surface Electromyogram Of The Lower Extremity Muscles Of Young Men And Women When They Are Squating Quietly Against The Wall

Usually the difference between exercise squat angle will affect the degree and effectiveness of muscle exercise.Static squat by the wall is developed from stationing movement in martial arts,It is consistent with the body's routine function activities such as going up and down the stairs,sitting,running,moving and jumping.It is one of the good sports for the body to exercise muscles and enhance physical fitness.Different wall static squatting angle on the degree of muscle exercise leads to different effect,and will also affect the knee patellofemoral force,patellofemoral joint sustained load stress easily leads to the wear and tear of articular cartilage,causing a variety of knee Lesions,According to different exercise needs,people can choose to rely on the angle of static squatting,and really do theoretical connection with practice,theory guiding practice.The model was constructed by means of literature review,experiment and mathematical statistics.The self-built model was used to calculate the force of the patellofemoral joint when the male and female were resting on the wall at 45 °,60 °,75 ° and 90 °respectively.A total of 18 healthy subjects(9 males and 9 females)were studied by literature review,experimental and mathematical statistics,they were asked to squat at different degree(45°?60°?75°and 90°)to the very tired state,in the entire process,the rectus femoris,medial and lateral femoral muscle contraction and muscle fiber recruitment levels,the contribution of muscle,the same wall static squat angle in the median frequency and average power frequency changes were studied,the experimental results were obtained through the statistics and analysis.result:1 Size of 4 angles patellofemoral joint force values: 90 °> 60 °> 45 °> 75 °.2 The multiples value of female?s patellofemoral joint force and weight is more than male ?s.3 No significant difference was found in rectus femoris,lateral femoral and medial iEMG muscle EMG score of male and femal(p <0.05).4 Contributions of muscle at four squat angles: lateral femoris> medial femoris> rectus femoris.5 Size of iEMG between different angles in the same muscle: 90 °> 75 °> 60 °> 45 °.6 Size of iEMG between different stages of the same muscle: Stage 5> Stage 1> Stage 4> Stage 3> Stage 2.7 The MPF and MF of the rectus femoris muscle,lateral femoral muscle and medial femur in the four squat angles were all decreased with the extension of exercise time.Conclusion:The internal force of patellofemoral joint is 3-5 times of body weight when male and female squat against the wall at 45,60,75 and 90 degrees.Compared with their own weight,the internal force of patellofemoral joint at four squatting angles against the wall is larger in females than in males,and the degenerative changes of knee joint are more likely to occur.The results of internal force analysis at different squatting angles against the wall show that the internal force of patellofemoral joint is 3-5 times larger than that of females.The internal force of patellofemoral joint was the greatest in both males and females at 90 degrees,followed by 60 degrees and 75 degrees,and the smallest in females and females at 45 degrees,60 degrees,75 degrees and 90 degrees.There were no significant differences in contraction characteristics,fatigue changes and internal force trend of patellofemoral joint during different phases of quadriceps femoris squatting with time prolonged,and there were no significant differences in the internal force trend of patellofemoral joint at different angles.Both men and women have the best exercise effect of lateral femoral muscle while rectus femoris has the least exercise effect.With the increase of squatting angle against the wall,the degree of muscle fiber recruitment increases.suggestions below:When using the squat on the wall to strengthen the muscle strength to prevent the joint injury,we can use the free time to practice many times and strengthen the muscle strength of the rectus femoris and the medial femoral muscle combined with other exercises to prevent the imbalance of the strength of the four muscles of the femoral head.The force size of the patellofemoral joint is larger than the male force at the same angle at 45,60,75 and 90 degrees on the wall.More attention should be paid to the protection and maintenance of the knee joint;in the choice of male and female sex at 45,60,75 and 90 degrees by the wall squat angle,only 90 degrees can be squatted by the wall when the muscle strength of the four head muscle is increased only,and when the force of the patellofemoral joint is too large,it can choose 75 and 45 degrees to sit on the wall.