Direct Relation of Acute Effects of Static Stretching on Isokinetic Torque Production With Initial Flexibility Level

Purpose: To examine the acute effect of a single static-stretching session of hamstring muscles on torque production in relation with individual flexibility. Methods: Maximal voluntary concentric torque of hamstring muscles was measured before and after a static-stretching session (6 x 30 s). Torque changes were correlated with the flexibility level determined at the onset of the experimental procedure. Results: The hamstring-stretching intervention significantly reduced maximal concentric torque in participants with low and high hamstring flexibility. Hamstring flexibility and torque decrease, determined immediately after the stretching procedure, were negatively correlated. Conclusions: Torque decrease measured after the static-stretching session is dependent on participant flexibility. Participants with low flexibility are much more likely to demonstrate large torque decreases poststretching.