Comparison of the immediate effect of neural mobilization versus muscle stretching on straight leg raising in asymptomatic individuals: a randomized clinical trial

Abstract

Introduction: Hamstring injuries are common among athletes and physically active individuals and are often associated with reduced muscle flexibility. Muscle stretching and neural mobilization techniques offer distinct approaches to improving joint range of motion. Although previous literature provides evidence of similar effects of both interventions on the range of motion in the straight leg raise test, no study has investigated their influence on sciatic neurodynamic tension. Objectives: To compare the immediate effect of a muscle stretching exercise program versus neural mobilization on the straight leg raise test in asymptomatic individuals. Methods: A randomized clinical trial was conducted with 40 asymptomatic adults. Sociodemographic and clinical characteristics were collected using a self-administered questionnaire. Sciatic nerve neurodynamic tension was assessed through the straight leg raise test and ultrasound imaging measurements (cross-sectional area and nerveto-skin distance). Participants were randomly assigned to two groups: the control group performed hamstring stretching exercises, while the experimental group received sciatic nerve mobilization. The effects of the interventions were compared using a mixed linear model for repeated measures. Results: Participants had a mean age of 30 years, with an equal sex distribution. After screening 140 individuals, the final sample was determined based on an estimated 20 participants per group. The results showed that both interventions increased hip flexion range of motion, with muscle stretching yielding a slightly superior effect (11.8°) compared to neural mobilization (7.9°). However, neither technique significantly altered the cross-sectional area or nerve-to-skin distance, suggesting that the observed effects were primarily musculoskeletal. Conclusion: Sciatic nerve mobilization and hamstring stretching exercises produced similar outcomes regarding sciatic neurodynamic tension in asymptomatic individuals.