Abstract

Introduction: some of the hamstring stretching techniques described in the literature are very similar to the neurodynamic tests (NDTs), which are designed to assess the integrity of the nervous system. The question of the specificity of these techniques on muscle tissue arises. During the NDTs, the structural differentiation (SD) manoeuvre allows discrimination if the source of the symptoms is neural or muscular. With the same purpose, SD could be included as possible reflex of the source of the tension felt during hamstring stretching techniques. Objective: to describe the effect of the SD in the tension felt by healthy subjects during hamstring stretching and self-stretching techniques. Material and methods: a descriptive observational study was designed. The sample was recruited from the students and staff of the University of Zaragoza. Straight Leg Raise (SLR), Passive Knee Extension (PKE), Maximum Hip Flexion (MHF) and a self-stretching technique were performed in all subjects. The symptoms response was classified according to the SD manoeuvre results. Results: a total of 54 subjects (108 limbs) with a mean age of 25 ± 4.6 participated in the study. The percentage of muscle responses was 26.9 %, 48.8 % and 81.48 % for SLR, PKE and MHF techniques, respectively. In the self-stretching technique the percentage of muscle responses was 20.4 %. Conclusions: the addition of the SD in the general procedure of stretching can be useful to differentiate the source of the tension generated by the techniques of hamstring stretching. Those stretching techniques with similar sequences of movement than NDTs had the largest number of neural responses. On the opposite hand, stretching techniques which used the maximum hip flexion appeared to be most specific for muscle tissue.