Effects Of The On-Court Movements On The Impact Load Of The Lower Extremities In Tennis

Objective: To collect the data of lower limb muscle activity and tibial tuberosity acceleration in different surfaces and on different lines,and compare the effects of different sites on the movement of lower limbs muscles and the impact load of lower limbs.Methods: A total of 14 male secondary athletes from Beijing Sports University were tested on two surface surfaces and four lines of forehand stroke.The data were collected by wireless surface electromyography and acceleration acquisition system(triaxial).The surface electromyography signal and tibial nodule acceleration data of rectus femoris,biceps femoris,tibialis anterior,medial gastrocnemius lateral head,medial head of gastrocnemius muscle and peroneus longus were calculated to calculate the surface electromyography Integral electromyography,RMS,median frequency and acceleration maximum amplitude,X axis acceleration vibration frequency,record X axis acceleration maximum amplitude appear time.Results: 1)The surfaces have no significant effect on the maximum amplitude of the acceleration in the vertical direction(P <0.05).2)There was no significant difference in the maximum amplitude of the acceleration in the vertical direction.There was no significant difference in the amplitude of the acceleration in the upper and lower directions.In the left and right direction,the maximum amplitude of acceleration in line 4 is the smallest.3)The surface of the surface of the lower limb muscles have a significant impact on the degree of activation,specifically in addition to the rectus muscle,the rest of the muscles in the hard ground root mean square amplitude And integral electromyography were greater than sand,and there is a significant difference.Conclusions:1.In the process of moving and hitting,the impact load on the lower extremity in the up and down the direction in the largest,followed by left and right direction,front and rear direction is the smallest.2.the impact load on lower extremity on hard tennis court are higher than the sand tennis court,and in the left and right and front and rear direction is more obvious.3.In the process of moving and hitting of four types of movements,he impact load on the lower limbs has no significant difference,only in the forehand sideways hit the impact of the lower limbs left and right direction was significantly lower than other lines.But with the increase of running distance,the impact load of lower limbs is increased,and the risk of injury increases.4.In the process of moving and hitting,on the hard court the activation of most muscles in the lower limbs was significantly higher than that in the sand court,indicating that the human body can adjust the Neuromuscular to deal with the impact of the surfaces material and impact load.