Systematic Reviews and Meta-analyses of Neural Mobilisation

Introduction

Systematic reviews and meta-analyses are a particularly high level of evidence (level 1) and they are used commonly to determine if an intervention is associated with clinical improvements.

It is important that many therapies undergo such investigation and, including neural mobilisation, the key question is whether evidence exists for it being effective, or not.

As a key part of neurodynamics, neural mobilisation (NM) is performed on many clinical problems, the most common of which being carpal tunnel syndrome, low back pain (LBP) and sciatica.

In terms of therapeutic efficacy, NM has now been studied numerous times, to the point where systematic reviews and meta-analyses can be done.  Discussed here are several such studies.


The first known systematic review of therapeutic efficacy of NM was done by Ellis and Hing (2008) in which the main findings were:

          -  there was evidence in favour of NM being effective but it was
              limited
          -  heterogeneity of sample groups was an issue
          -  this article rightly demonstrated that there is a need for more
              high quality studies.


Since then, much has been done and the next two systematic reviews show even better results. 


Basson et al 2017 showed:

          -  for primary outcomes (pain, disability, function), 40 studies
               were included
          -   17 studies were of low risk of bias
          -  meta-analysis could be done on self-reported outcomes
              (eg. Oswestry).


Results 

There was evidence for:
          -  reduced neural oedema (eg. carpal tunnel syndrome)
          -  due to scarcity of studies or conflicting results, the effect of NM
              remained uncertain for post-operative LBP (eg. lumbar fusion),
              cubital tunnel syndrome and lateral epicondylalgia
          -  improvements were supported in chronic neck pain, chronic
              LBP and disability (Oswestry) associated with LBP.


Summary Points 

There was level 1 evidence for an effect with NM for:

          -  intensity of chronic neck pain
          -  intensity of chronic LBP
          -  disability associated with LBP.


This analysis used heterogeneous grouping in terms of clinical conditions and body regions.

What happens when a systematic review is  performed on a less heterogeneous group (Neto et al 2018)?

This one focused on the lower quarter.

Study Summary

          -  groups:  asymptomatic subjects, LBP patients
          -  45 studies selected
          -  10 in meta-analysis; 5 studies on asymptomatic subjects, 5 LBP
              population studies

          -  included 502 subjects
          -  quality of included studies “fair to good" with a mean PEDro
              score of 6.3 (4-8).


Results 

Moderate effect size (g = 0.73) occurred in flexibility in healthy adults.

Large effect sizes occurred for LBP:

          -  pain reduction (g = 0.82)
          -  disability reduction (g = 1.59)
          -  more quality studies needed.


Summary Points Overall

There is level 1 evidence for:

          -  improvement in chronic neck pain
          -  
improvement with NM in lower quarter clinical problems
          -  moderate effect sizes for NM technique in asymptomatic
​              subjects (eg. hamstring length)

          -  large effect sizes for NM treatment of LBP and disability
              associated with LBP.



It can now be seen that, not only is there level 1 evidence for neural mobilisation being effective for the above conditions, but it seems that, when studied more homogeneously and with higher quality studies, the results become more discernible.


So, even though this is rather strong evidence, a question is whether these studies can be directly generalised to each patient we see.

Clearly, it still is not possible to get away from detailed examination and treatment of the patient as an individual.  However, these studies give confidence in the future of neurodynamics and justify more study of the subject.

Congratulations to the authors for such good work!



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REFERENCES

Basson A, Olivier B, Ellis R, Coppieters M, Stewart A, Mudzi A 2017 The effectiveness of neural mobilization for neuromusculoskeletal conditions: a systematic review and meta- analysis.   Journal of Orthopaedic and Sports Physical Therapy 47 (9): 593-615.

Ellis R, Hing W 2008 Neural Mobilization: A systematic review of randomized controlled trials with an analysis of therapeutic efficacy.  Journal of Manual and Manipulative Therapy 16 (1): 8–22.

Neto T, Freitas S, Marques M, Gomes, L, Andrade R 2018 Effects of lower body quadrant neural mobilisation in healthy and low back pain populations: a systematic review and meta-analysis.  Musculoskeletal Science and Practice 27: 14-2
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