Immediate effects of different stretching methods on knee joint muscle strength and vertical jump performance of healthy adults
BACKGROUND:Static stretching effectively improves joint motion amplitude,dynamic stretching effectively improves muscle strength and athletic performance through the post-activation strengthening effect of the muscles.OBJECTIVE:To explore the immediate effects of different stretching methods on knee joint muscle strength and vertical jump performance,and provide theoretical support for seeking the best stretching plan,improving sports performance,and preventing training injuries.METHODS:Thirty healthy college students were randomly recruited.The Biodex isokinetic muscle strength system,Qualisys infrared motion capture system,and AMTI three-dimensional force measurement platform were used to collect knee joint muscle strength and vertical jump data after static quadriceps/hamstring stretching,dynamic quadriceps/hamstring stretching,dynamic quadriceps/static hamstring stretching,and static quadriceps/dynamic hamstring stretching.The peak torque,average power,vertical jump height,peak vertical ground reaction force,and joint motion amplitude of the knee joint were used to evaluate the muscle strength and vertical jump performance of the knee joint.RESULTS AND CONCLUSION:Compared with the static quadriceps/hamstring stretching,dynamic quadriceps/hamstring stretching significantly increased knee joint peak torque,average power,and vertical jump height(P<0.05);dynamic quadriceps/static hamstring stretching and static quadriceps/dynamic hamstring stretching significantly increased knee extension and flexion peak torque and average power(P<0.05).Compared with static quadriceps/hamstring stretching,second peak vertical ground reaction force significantly decreased after static quadriceps/dynamic hamstring stretching(P<0.05);lower limb joint motion amplitude significantly increased after dynamic quadriceps/hamstring stretching(P<0.05).These findings indicate that immediate agonists/antagonistic muscle dynamic stretching and agonists dynamic stretching/antagonistic muscle static stretching significantly improve knee joint muscle strength,vertical jump performance,and joint motion amplitude.A larger joint motion amplitude is beneficial for improving athletic performance and better absorbing ground impact during landing.At the same time,agonists muscle dynamic stretching/antagonistic muscle static stretching is better than agonists/antagonistic muscle dynamic stretching to improve knee joint muscle strength,and agonists muscle static stretching/antagonistic muscle dynamic stretching is beneficial for improving the energy absorption capacity during vertical jumping and reducing the risk of injury during landing.