Hypoalgesic and Motor Effects of Neural Mobilisation versus Soft-Tissue Interventions in Experimental Craniofacial Hyperalgesia: A Single-Blinded Randomised Controlled Trial

Abstract

Objective: The present trial aimed to compare the effects of the mobilisation of the nervous system (NS) to those of a soft-tissue intervention in subjects exposed to an experimentally induced hyperalgesia of the masticatory muscles.

Methods: The study was a single-blinded randomised controlled trial. A total of 49 participants (mean ± SD age: 41 ± 11 years; 61% female) with latent myofascial trigger points (LMTrPs) in the craniofacial region were randomly assigned to one of three groups: neural mobilisation (NM), soft-tissues techniques and stretching (STT-S), and control group (CG). An initial assessment (baseline) was performed before the provocation chewing masticatory test. The pre-treatment measurements were registered 24 h later. Next, the randomised intervention was applied, and afterwards, post-treatment data were obtained. Outcome measures included pain-free maximum mouth opening (MMO), pressure pain thresholds (PPTs) in the trigeminal and cervical region, and trigeminal and cervical two-point discrimination (TPD).

Results: ANOVA revealed significant differences for the time × group interaction for pain-free MMO and PPTs. The results showed an improvement in the MMO and the PPTs for NM and STT-S groups but not for the CG. There were no differences between the NM and STT-S groups. However, the effect sizes were large for the NM and medium for the STT-S. No differences were found for TDP between groups nor over time.

Conclusions: The results show that with NM and STT-S techniques, we could influence motor and sensory variables in asymptomatic subjects with LMTrPs after a masticatory provocation test. Both techniques increased MMO and PPTs in the short term. These beneficial effects lead us to consider the importance of including these methods in clinical practice.

Keywords: manual therapy; myofascial trigger points; neural mobilisation; neurodynamics; pressure pain threshold; provocation chewing test; soft-tissue; trigeminal nerve.

Figure 1

Flow diagram and procedure.

Figure 2

Comparison of Pressure Pain Threshold results for each of the treatment groups, at each of the measure time-points. (A) Masseter muscle. (B) Temporalis muscle. Columns represent the mean and error bars represent standard deviation. NM, neural mobilisation. STT-S, soft-tissue techniques and stretching. CG, control group. * p < 0.05; ** p < 0.001.

Figure 3

(A) Comparison of pressure pain threshold results of the upper trapezius muscle for each of the treatment groups, at each of the measure time-points. (B) Comparison of Maximal Mouth Opening for each of the treatment groups, at each of the measure time-points. Columns represent the mean and error bars represent standard deviation. NM, neural mobilisation. STT-S, soft-tissue techniques and stretching. CG, control group. ** p < 0.001.