The Effects of High-Intensity, Low-Duration and Low-Intensity, High-Duration Hamstrings Static Stretching on Contralateral Limb Performance

Introduction: Increases in contralateral range of motion (ROM) have been shown following acute high-intensity and high-duration static stretching (SS) with no significant change in contralateral force, power, and muscle activation. There are currently no studies comparing the effects of a high-intensity, low-duration (HILD) or low-intensity, high-duration (LIHD) SS on contralateral performance. Purpose: The aim of this study was to examine how HILD and LIHD SS of the dominant leg hamstrings influence contralateral limb performance. Methods: Sixteen trained participants (8 females, 8 males) completed three SS interventions of the dominant leg hamstrings; 1) HILD (6x10s at maximal point of discomfort (POD)), 2) LIHD (6x30s at initial POD), and 3) control. Dominant and non-dominant ROM, maximal voluntary isometric contraction (MVIC) forces, muscle activation (electromyography (EMG)), unilateral CMJ and DJ heights were recorded pre-test and 1-minute post-test. Results: There were no significant contralateral ROM or performance changes. Following the HILD condition, the post-test ROM for the stretched leg (110.612.60) exceeded the pre-test (106.09.00) by 4.2% (p=0.008). Similarly, with LIHD, the stretched leg post-test (112.216.50) also exceeded (p=0.06) the pre-test ROM (109.316.20) by 2.6%. There were large magnitude impairments, evidenced by main effects for testing time for force, instantaneous strength, and associated EMG. A significant ROM interaction (p=0.02) showed that with LIHD, the stretched leg significantly (p=0.05) exceeded the contralateral leg by 13.4% post-test. Conclusion: The results showing no significant increase in contralateral ROM with either HILD or LIHD SS suggesting the interventions may not have been effective in promoting crossover effects.