Research Review By Dr. Michael Haneline©

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Date Posted:

September 2017

Study Title:

Effects of lower body quadrant neural mobilization in healthy and low back pain populations: A systematic review and meta-analysis

Authors:

Neto T, Freitas S, Marques M, Gomes L et al.

Author's Affiliations:

Faculdade de Motricidade Humana, Universidade de Lisboa (Faculty of Human Motricity), University of Lisbon, Portugal; Benfica LAB, Sport Lisboa e Benfica, Portugal; CIPER - Universidade de Lisboa, Portugal; Escola Superior de Saúde, Instituto Politecnico de Setúbal, Portugal; Laboratory “Movement, Interactions, Performance”, University of Nantes, UFR STAPS, France.

Publication Information:

Musculoskeletal Science & Practice 2017; 27: 14-22. doi:10.1016/j.msksp.2016.11.014.

Background Information:

Neural mobilization (NM, colloquially referred to as “nerve flossing”) involves the application of tensioning and/or sliding forces to peripheral nerves with the purpose of improving flexibility and neural excursion, which has been shown to bring about a reduction of pain.

It has been reported that nerves may exhibit altered structural properties and associated compromised function in patients with peripheral neuropathies. NM can improve nerve dysfunction by stimulating the nerve’s blood supply, improving axoplasmic flow, and releasing scar tissue between the nerve and surrounding tissues (1).

NM techniques have been shown to be effective for several neuromuscular disorders (e.g. cervicobrachial pain, lateral epicondylalgia and carpal tunnel syndrome). NM is also used to treat lower back pain (LBP), with relief purportedly obtained by reducing the mechanosensitivity of the patient's lower body quadrant (2).

Several systematic reviews have considered the effects of NM in patients with upper body quadrant dysfunctions. However, despite recent NM studies that have investigated lower back flexibility in healthy populations and the effects of NM on pain and disability in people with LBP, no related systematic reviews or meta-analyses have been conducted. Therefore, the purpose of this study was to systematically review relevant randomized controlled trials (RCTs) on these topics.

Pertinent Results:

After screening the title and abstract of 4928 articles, the full-text of 45 studies was analyzed, resulting in 10 being included in the meta-analysis.

A total of 502 participants were involved in the 10 studies, with 246 of them being LBP participants and 256 healthy participants. Five of the studies investigated the effects of NM techniques in healthy participants and five studies considered people with LBP.

The methodological quality of the included studies ranged from 4 to 8 on the 10-point PEDro scale, with an average score of 6.3 points. Studies with PEDro scores > 8 were considered excellent, 6-8 good, 4-5 fair, and < 4 poor.

Neural mobilization techniques were most commonly performed in the slump test position. The number of NM sessions ranged from 1 to 90, with sessions lasting from 60 seconds to 300 seconds. From 1 to 45 repetitions per session of NM technique were applied, most commonly 5 repetitions.

Five studies investigated the use of NM to increase flexibility, which showed a medium size positive effect that was considered significant.

Another five studies considered the effects of the NM techniques on pain, which produced large effect sizes in patients with LBP.

Three studies considered the effects of NM on disability; the overall effect size was large favoring the use of NM in people with LBP.

Clinical Application & Conclusions:

This systematic review and meta-analysis showed that the evidence supports the use of neural mobilization (NM) techniques applied to the lower body quadrant. Flexibility was improved in healthy subjects and people with LBP experienced pain relief and functional improvements.

Nevertheless, more high quality RCTs that involve longer follow-ups and include better comparison groups are needed to provide solid conclusions regarding the effectiveness of NM interventions.

Study Methods:

This was a systematic review and meta-analysis in which the following databases were searched: PubMed, PEDro, Web of Science, Scielo, and Cochrane Central Register of Controlled Trials. In addition to the electronic searches, references from the reference sections of the included studies and earlier reviews were manually searched.

Articles were screened for inclusion independently by 2 reviewers using the following inclusion criteria:
  • Subjects had to be over 18 years of age;
  • both healthy and LBP participants were included;
  • at least one of the following outcomes had to be involved: pain intensity, disability, or lower limb flexibility; and
  • randomized clinical trials had to involve NM techniques (i.e. sliding or tensioning) targeting the lower body quadrant.
Studies were excluded if they involved populations with:
  • other neuromuscular or rheumatic disorders,
  • post-surgical conditions, or
  • pregnancy.
The quality of the selected studies was assessed independently by two reviewers using the PEDro scale. Any disagreements were resolved by reaching a consensus between the reviewers.

There were enough similarities between the included studies to pool the data and perform meta-analyses. Separate meta-analyses were performed for each outcome – pain, disability and flexibility.

Study Strengths / Weaknesses

This was a well-done systematic review and meta-analysis, although the number of studies located was fairly small. In fact, only 3 trials were used in one of the meta-analyses.

Even though this review was well-done, the typical weaknesses of such reviews should be considered, including:
  • the possibility that studies might have been missed during the literature search;
  • publication bias, whereby studies that do not show a positive effect are less likely to be published;
  • review authors having personal viewpoints that create biases; and
  • misrepresentation or misinterpretation of the source data.

Additional References:

  1. Walsh M. Upper Limb Neural Tension Testing and Mobilization: Fact, Fiction, and a Practical Approach. J Hand Ther. 2005; 18: 241–58.
  2. Coppieters M, Kurz K, Mortensen T, Richards N, Skaret I, McLaughlin L, et al. The impact of neurodynamic testing on the perception of experimentally induced muscle pain. Man Ther. 2005; 10(1): 52-60.