Effect of Short Term Static and Dynamic Stretching Exercise on Conventional and Functional Ratio of Hamstring-to- Quadriceps in Female Athletes

The present study aimed to determine short term static and dynamic stretching exercise on peak eccentric torque of hamstring muscle and conventional and functional rate of hamstring to quadriceps in female athletes. Sixteen female futsal athletes (weight: 52.65.83, age: 24± 4.2) were participated in this study who had no history of injury in lower limb. They were asked to be in order to measure isokinetic peak torque of quadriceps and hamstring muscles in both concentric and eccentric contractions in one of the states of no stretch (control), static and dynamic stretch. The participants did four stretching exercises for muscle groups of lower limbs (hamstring, quadriceps, adductors and Psoas). Two 30-second stretching exercises were done in static state and fifteen 2-second exercises with a 20-second interval rest were done in dynamic state. Fifteen minutes after stretching exercises the isokinetic tests were conducted by biodex in order to determine maximum concentric and eccentric torque as well as functional and conventional ratio of hamstring to quadriceps muscles at velocity of 60 and 180 degrees/second. The results were analyzed at P≤0.05 using analysis of variance with repeated measurements. According to the results, 15 minutes after stretching exercise, the maximum extrinsic torque of hamstring decreased significantly in dynamic status. No significant difference was shown in current strength ratio of hamstring to quadriceps after doing stretching exercise in static and dynamic states, however, significant decrease in functional ratio in dynamic state compared to static state was found (P≤0.05). It seems, although a 15- minute passive rest could reduce some undesirable effects of static stretching exercises, the dynamic stretching exercises should be recommended cautiously.