Impact of Spinal Manipulation on Cortical Drive to Upper and Lower Limb Muscles.

Authors: Haavik H, Niazi IK, Jochumsen M, Sherwin D, Flavel S, Türker KS.

Published in: Brain Sci. 2016 Dec 23;7(1). pii: E2. doi: 10.3390/brainsci7010002.

Abstract

This study investigates whether spinal manipulation leads to changes in motor control by measuring the recruitment pattern of motor units in both an upper and lower limb muscle and to see whether such changes may at least in part occur at the cortical level by recording movement related cortical potential (MRCP) amplitudes. In experiment one, transcranial magnetic stimulation input-output (TMS I/O) curves for an upper limb muscle (abductor pollicus brevis; APB) were recorded, along with F waves before and after either spinal manipulation or a control intervention for the same subjects on two different days. During two separate days, lower limb TMS I/O curves and MRCPs were recorded from tibialis anterior muscle (TA) pre and post spinal manipulation. Dependent measures were compared with repeated measures analysis of variance, with p set at 0.05. Spinal manipulation resulted in a 54.5% ± 93.1% increase in maximum motor evoked potential (MEPmax) for APB and a 44.6% ± 69.6% increase in MEPmax for TA. For the MRCP data following spinal manipulation there were significant difference for amplitude of early bereitschafts-potential (EBP), late bereitschafts potential (LBP) and also for peak negativity (PN). The results of this study show that spinal manipulation leads to changes in cortical excitability, as measured by significantly larger MEPmax for TMS induced input-output curves for both an upper and lower limb muscle, and with larger amplitudes of MRCP component post manipulation. No changes in spinal measures (i.e., F wave amplitudes or persistence) were observed, and no changes were shown following the control condition.

These results are consistent with previous findings that have suggested increases in strength following spinal manipulation were due to descending cortical drive and could not be explained by changes at the level of the spinal cord. Spinal manipulation may therefore be indicated for the patients who have lost tonus of their muscle and/or are recovering from muscle degrading dysfunctions such as stroke or orthopaedic operations and/or may also be of interest to sports performers. These findings should be followed up in the relevant populations.

Effect of CSvsTS manipulation on peripheral neural features and grip strength : RCT

Author: Bautista-Aguirre F, Oliva-Pascual-Vaca Á, Heredia-Rizo AM, Boscá-Gandía JJ, Ricard, Rodriguez-Blanco

Published in: Eur J Phys Rehabil Med. 2017 Jun;53(3):333-341.

Abstract

BACKGROUND:

Cervical and thoracic spinal manipulative therapy has shown positive impact for relief of pain and improve function in non-speci

fic mechanical neck pain. Several attempts have been made to compare their effectiveness although previous studies lacked a control group, assessed acute neck pain or combined thrust and non-thrust techniques.

AIM:

To compare the immediate effects of cervical and thoracic spinal thrust manipulations on mechanosensitivity of upper limb nerve trunks and grip strength in patients with chronic non-specific mechanical neck pain.

DESIGN:

Randomized, single-blinded, controlled clinical trial.

SETTING:

Private physiotherapy clinical consultancy.

POPULATION:

Eighty-eight subjects (32.09±6.05 years; 72.7% females) suffering neck pain (grades I or II) of at least 12 weeks of duration.

METHODS:

Participants were distributed into three groups: 1) cervical group (N.=28); 2) thoracic group (N.=30); and 3) control group (N.=30). One treatment session consisting of applying a high-velocity low-amplitude spinal thrust technique over the lower cervical spine (C7) or the upper thoracic spine (T3) was performed, while the control group received a sham-manual contact. Measurements were taken at baseline and after intervention of the pressure pain threshold over the median, ulnar and radial nerves. Secondary measures included assessing free-pain grip strength with a hydraulic dynamometer.

RESULTS:

No statistically significant differences were observed when comparing between-groups in any of the outcome measures (P>0.05). Those who received thrust techniques, regardless of the manipulated area, reported an immediate increase in mechanosensitivity over the radial (both sides) and left ulnar nerve trunks (P<0.05), and grip strength (P<0.001). For those in the control group, right hand grip strength and pain perception over the radial nerve also improved (P≤0.025).

CONCLUSIONS:

Low-cervical and upper-thoracic thrust manipulation is no more effective than placebo to induce immediate changes on mechanosensitivity of upper limb nerve trunks and grip strength in patients with chronic non-specific mechanical neck pain.

CLINICAL REHABILITATION IMPACT:

A single treatment session using cervical or thoracic thrust techniques is not enough to achieve clinically relevant changes on neural mechanosensitivity and grip strength in chronic non-specific mechanical neck pain.