The acute effects of different stretching exercises on isokinetic strength parameters in volleyball players

The purpose of this study is to analyze the acute effects of 3 different stretching exercises which are static, dynamic and PNF on isokinetics. The study includes 20 volunteers who play volleyball in boys teams. Isokinetics strength measurements were made in a concentric mode at 60?/sec and 300?/sec. Before testings, the participants had a warm-up on the treadmill for 5 minutes, and then by selecting randomly, they performed 3 different stretching exercices that are static, dynamic and PNF for shoulder and knee on different days for 30 seconds by repeating 3 times with 20 second breaks at intervals. According to the results of statistical analysis, no significant difference was found between peak torque values for right and left shoulder in internal and external rotation at 60?/sec and 300?/sec. No statistical difference was found between peak torque values for right knee extension and left and right flexion at 60?/sec measured after 3 different stretching trainings. Besides, no statistical difference was found between peak values of left knee extension at 60?/sec after 3 different stretching trainings. The average peak torque value achieved after dynamic stretching was higher than the peak torque value achieved after static and PNF stretchings. Also, no statistical significance was found between peak torque values for left and right knee extension and right and left flexion at 300?/sec measured after the exercises of static, dynamic and PNF. As a result, the findings of the study indicated that static and PNF stretchings caused decreases in acute muscle strength in comparison to dynamic stretching.Key Words: PNF stretching, Static stretching, dynamic stretching, volleyball, isokinetic strength