Acute effects of a single neurodynamic mobilization session on range of motion and H-reflex in asymptomatic young subjects: A controlled study

Abstract

Neurodynamic techniques have yielded good clinical results in the treatment of various pathologies. The objective of this study is to examine the short-term effects of neurodynamic techniques of the sciatic nerve on hip ROM (range of motion) and on the amplitude and latency of the soleus H-reflex and M-waves, in young asymptomatic subjects. In a double-blind controlled trial design, 60 young asymptomatic participants were randomly assigned into six groups with different levels of manipulation of the sciatic nerve. The passive straight leg raise test was used to evaluate the hip ROM amplitude. All evaluations were performed before, 1 min after, and 30 min after intervention. For each time-point, spinal and muscle excitability were also tested. ROM increased in all groups, but none of the treatment groups had superior effects than the group with no treatment. This means that ROM testing maneuvers increased ROM amplitude, with no add-on effect of the proposed neurodynamic techniques. Neurophysiological responses changed similarly in all groups, showing that the aftereffects were not intervention-specific. We observed a significant negative association between the change in limb temperature and the change in latencies of all potentials. ROM-testing procedures performed repeatedly increase ROM amplitude. This observation should be considered when evaluating the aftereffects of therapeutic interventions on ROM amplitude. None of the explored neurodynamic techniques produced acute aftereffects on hip ROM amplitude, spinal or muscle excitability different to the induced by the ROM testing maneuver.

Keywords: H-reflex; muscle stretching exercises; nerve tissue; physical therapy modalities; range of motion articular.

FIGURE 1

Testing and intervention protocols sequence. (a) Initial position for ROM evaluation. (b) Final position for ROM evaluation. (c) Initial position for neural mobilization group. (d) Final position for neural mobilization group. (e) Position for no‐neural mobilization group.

FIGURE 2

(a) Amplitudes of the M‐waves during the recording of the H₅₀ along the three time‐points, in the six groups. Amplitudes were unchanged the along testing times in all groups. (b) The same plot as (a) at different y‐axis scale. (c) The same variable that (a) and (b) but pooling groups as their responses along time were not different for the groups, dots are individuals' responses. (d) M‐wave amplitudes during H_MAX recording at the testing time‐points, for all groups. (e) The same variable that (d) at different y‐axis scale. (f) The same variable that (d) and (e) but pooling groups, since their responses along time were not different for the groups, dots are individuals' responses. (g) CMAP amplitudes at the testing time‐points, for the six groups. (h) The same variable that (g) but pooling groups since their responses along time were not different, dots are individuals' responses. Amplitudes remained unchanged in all groups along time. Scores are means and standard deviations.

FIGURE 3

Amplitudes of the H₅₀‐waves (a), and the H_MAX (b) along the three time‐points in the six groups, responses between groups along pre‐post‐post2 did not differ significantly. (c) Same plot that (a) and (b) but pooling groups, responses for H₅₀ did not differ in a significant way from responses for H_MAX, both increased along time as shown in (d). Insets d.1 and d.2 represent individuals' responses. Scores are means and standard deviations. *p < 0.05.

FIGURE 4

M‐wave latencies changes along time for the different groups when acquiring H₅₀ (a), H_MAX (b), and CMAP (c). Section (d) shows the same responses with groups pooled (as responses along time did not differ for the groups). Responses for the three types of M responses along pre‐post‐post2 did not differ between them, the increase was significant as shown in section e. Insets e.1, e.2 and e.3 represent individuals' responses. Scores are means and standard deviations. **p < 0.01; ***p < 0.001.

FIGURE 5

H‐wave latencies changes along time for the different groups when acquiring H₅₀ (a) and H_MAX (b). Section (c) shows the same responses with groups pooled (since responses along time did not differ in a significant level for the groups). Responses for the two types of H responses along pre‐post‐post2 did not differ between them, both increased as shown in section (d). Insets d.1 and d.2 represent individuals' responses. Scores are means and standard deviations. ***p < 0.001.

FIGURE 6

(a) Hip ROM amplitude change along the three testing times for the different groups. Section (b) shows the same responses with groups pooled (as responses along time did not differ between groups). In all groups, ROM increased from PRE to POST, and the change remained at post2. Inset b.1 represents individuals' responses. Scores are means and standard deviations.

FIGURE 7

(a) Change in limb temperature during the testing of the potentials at the different time‐points (means and standard deviations). (b) Scatter‐plot of the association between the changes the amplitude of the potentials along the whole protocol (normalized scores – x axis) and changes in limb temperature (° – y axis). (c) Scatter‐plot of the association between the changes the latency of the potentials along the whole protocol (ms – x axis) and changes in limb temperature (° – y axis). Changes in latencies were significantly associated to changes in limb temperature; this effect was not observed for the amplitudes of the potentials.