Comparison of the Quadriceps s EMG and Patellofemoral Force at Different Static Squatting Angles

The subjects do different angles knees static squatting exercises and test the surface Electromyography( s EMG) of the thigh quadriceps,and combined with the knees patellofemoral joint stress analysis under different angles to provide the theory basis and the reference value of clinical prevention and control of patellar strain,30 healthy male college students were selected respectively to do knees flexion 30°,45°,60° static squatting exercises,through the s EMG analysis and three-dimensional motion capture system to collect each subject s EMG parameters and kinematic parameters variations,and with the principles of mechanics calculated the patellofemoral joint force.When 45° static squatting,the quadriceps i EMG was the maximum value;With each angle of static squatting,the vastus lateralis is the largest amount of discharge,the rectus femoris is the smallest;During static squatting MPF,MF values of quadriceps radiate decreasing trend,but in static squatting at 45° MPF,MF fastest decline in value;When static squatting patellofemoral force increased with the increasing of the angle.Conclusion:It was found that in 45° flexion static squatting when compared to 30° and 60°,the easiest to reach quadriceps fatigue,and exercise better results,in which the vastus lateralis muscle was the most important working muscles when squatting.It is recommended that the patella strain patients do static squatting exercises according to their own feeling of pain in 30° ~ 60° range for training,but should avoid static squatting than 60° angle to be protected from excessive force to cause damage again.