Unilateral static and dynamic hamstrings stretching increases contralateral hip flexion range of motion

Area of Science:

• Sport and Exercise Science
• Biomechanics
• Physiology

Background:

• Static stretching (SS) and dynamic stretching (DS) can impact limb performance.
• Non-local muscle fatigue (NLMF) describes fatigue effects in non-exercised limbs, with mixed research findings.
• Limited research exists on the effects of acute SS or DS on contralateral flexibility, torque, or power.

Purpose of the Study:

• To investigate the acute effects of unilateral static stretching (SS) and dynamic stretching (DS) on contralateral hip flexor range of motion (ROM), torque, and power.
• To examine potential non-local effects of stretching on the non-stretched limb.

Main Methods:

• Fourteen highly trained subjects underwent separate sessions of unilateral hip flexion SS or DS (8 repetitions of 30s).
• Hip flexor ROM, isokinetic leg flexion torque, and power were measured in both the stretched and contralateral limbs at 1 and 10 minutes post-intervention.
• Measurements included isokinetic testing at 60°/s and 300°/s.

Main Results:

• Dynamic stretching (DS) significantly increased ROM in the stretched limb by 6.3% at 10 minutes.
• Both SS and DS significantly increased contralateral hip flexor ROM: SS by 5.7% (1 min) and DS by 7.1% (1 min) and 8.4% (10 min).
• No significant differences in ROM changes were observed between stretching conditions or limbs, and no stretch-induced changes in isokinetic torque or power were found.

Conclusions:

• Unilateral static stretching (SS) and dynamic stretching (DS) can augment contralateral limb range of motion (ROM).
• These findings suggest that stretching may increase stretch tolerance in non-exercised limbs.
• Acute stretching interventions do not appear to impair contralateral limb torque or power production.