Optimal Duration of Stretching of the Hamstring Muscle Group

OBJECTIVE: To explore the effect of variable stretching intervals on neural function and ROM. DESIGN: Randomized controlled trial Participants: In this trial, 168 participants diagnosed with tight hamstring muscles (defined as the inability to extend the knee to less than 20° of knee flexion) were randomly assigned to the control group or one of the 3 intervention groups Interventions: The three experimental groups was stretched for 15, 30, and 60 seconds, respectively the control group did not stretch Main Outcome Measures: The neurophysiological outcome measures included peak to peak somatosensory evoked potential for dermatomes L3,L4,L5, and S1. Secondary outcome measures included knee ROM. All outcome measures were assessed immediately after the treatment session and 24 hours after the treatment session.