Optimal Duration of Stretching of the Hamstring Muscle Group

Overview

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.

A prospective, blinded, parallel-group, randomized clinical trial will be conducted in the research laboratory of our university. The patients will participate in the study after signing an informed consent form prior to data collection. Inclusion Criteria Subjects who demonstrate "tight" hamstring muscles, defined as inability to extend the knee to less than 20 degrees of knee flexion with the femur held at 90 degrees of hip flexion while the person was positioned supine. Subjects will also be screened to rule out knee joint flexion contractures by checking knee extension ROM, while they were lying in a prone position Exclusion Criteria Using of medical aids, and suffering from any neurological or cognitive impairment, limiting cardio-respiratory conditions, or had undergone recent surgery (within the past 12 months). Having any hip or knee replacements or any history of pathology in the low back, hips, or knees for the 3 months prior to the study Participants will be divided into four groups according to the stretching duration time (15, 30, and 60s, and the fourth group, which served as a control, did not stretch). The patients will randomly assigned to one of the four groups as follows. The randomization process will be based on permuted blocks of variable sizes. Each random permuted block, created randomly by a number generator, will be transferred to a sequence of consecutively numbered, opaque, sealed envelopes that will be kept in a locked drawer until needed. Once a subject was formally included in the trial, the next envelope in the sequence was opened by the researcher in the presence of the subject who would be assigned to a group according to the number found in the envelope.