The sympathetic and hypoalgesic effects of spinal mobilisations: a systematic review

Purpose

To systematically review randomised controlled trials that assess the effectiveness of spinal mobilisations with regard to hypoalgesic and sympathetic nervous system (SNS) responses in healthy populations or in patients with cervical, thoracic or lumbar pain.

Approach

A sensitive topic-based search strategy was designed for individual databases. Healthy populations, or patients >18 yrs with cervical, thoracic or lumbar pain were included. Randomised controlled trials (RCT) that compared rates, sets, duration or amplitudes using at least one physiologic outcome measure to determine the hypoalgesic and/or SNS effects of spinal mobilisation were included. Studies not in English, with spinal mobilisation used in combination with others or with movements were excluded. Risk of bias was assessed using the Cochrane Back Review Group guidelines. Strength of recommendations were assessed using GRADE.

Outcomes

Results: N=8 articles (RCTs) with a sample size of n=492 in total met the inclusion criteria. Participants were either asymptomatic (n=6 studies) or with chronic cervical pain (n=2 studies). Six studies were considered low risk of bias, and two high risk of bias. Studies evaluating SNS effects found: a statistically significant difference in skin conductance (SC) after mobilisation compared to placebo and/or control (n=3); and no statistically significant difference in heart rate, systolic or diastolic blood pressure after mobilisation compared to placebo (n=1). Studies evaluating hypoalgaesic effects found: a statistically significant difference in pressure pain threshold (PPT) after mobilisation compared to placebo and/or control (n=1); and no statistically significant difference in PPT after mobilisation compared to high velocity low amplitude thrusts (HVLA), placebo and/or control (n=3). Additionally, higher force magnitude of mobilisation (90-N) did not lead to a significant increase in PPT compared to a lower force magnitude (30-N) (n=1); and comparing rates (2Hz vs. 3Hz) only 3Hz showed a significant increase in SC compared to the placebo and control conditions.

Conclusion(s): Overall, very low quality of evidence for the use of spinal mobilisations, which affect the pain and the SNS was found. Specifically, 1. very low evidence to support the effect of passive spinal mobilisations versus no treatment on PPT measurements in healthy subjects; 2. very low evidence to support the effect of passive spinal mobilisations versus placebo on SNS measurements in healthy subjects; and 3. very low quality evidence to support the effect of passive spinal mobilisations versus HVLA thrust on PPT measurements in healthy subjects. To understand the sympathetic and hypoalgesic effects of spinal passive accessory mobilisations, high quality studies in a symptomatic LBP population are necessary.

Cost and savings

No further information. 

Implications

This systematic review was the first to review passive spinal mobilisations along the three different regions of the spine with regards to hypoalgesic, and SNS effects. The review not only provides the quality of individual studies, but provides GRADE evaluation of topic areas. It has highlighted the need for high quality studies on symptomatic participants to understand the effects of this commonly used physiotherapy modality.

Top three learning points

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Funding acknowledgements

We would like to acknowledge the generosity of the Ministry for Education, Saudi Arabia.