The effects of a single session of chiropractic care on strength, cortical drive, and spinal excitability in stroke patients

Abstract

The objective of this study was to investigate whether a single session of chiropractic care could increase strength in weak plantar flexor muscles in chronic stroke patients. Maximum voluntary contractions (strength) of the plantar flexors, soleus evoked V-waves (cortical drive), and H-reflexes were recorded in 12 chronic stroke patients, with plantar flexor muscle weakness, using a randomized controlled crossover design. Outcomes were assessed pre and post a chiropractic care intervention and a passive movement control. Repeated measures ANOVA was used to asses within and between group differences. Significance was set at p < 0.05. Following the chiropractic care intervention there was a significant increase in strength (F (1,11) = 14.49, p = 0.002; avg 64.2 ± 77.7%) and V-wave/Mmax ratio (F(1,11) = 9.67, p = 0.009; avg 54.0 ± 65.2%) compared to the control intervention. There was a significant strength decrease of 26.4 ± 15.5% (p = 0.001) after the control intervention. There were no other significant differences. Plantar flexor muscle strength increased in chronic stroke patients after a single session of chiropractic care. An increase in V-wave amplitude combined with no significant changes in H-reflex parameters suggests this increased strength is likely modulated at a supraspinal level. Further research is required to investigate the longer term and potential functional effects of chiropractic care in stroke recovery.

Investigating the Effects of Chiropractic Spinal Manipulation on EEG in Stroke Patients

“…The increase observed in the present study may reflect an improvement in early sensorimotor function that is related to the observed increase in strength found in a recent study of chronic stroke survivors after a single session of chiropractic spinal manipulation [41]. In that study [41], Holt et al investigated the effect of chiropractic spinal manipulation on motor recovery in a chronic stroke population and found that, on average, plantarflexion muscle strength increased by approximately 64% after a single session of chiropractic care.…”

“…It is, therefore, interesting that the chiropractic intervention showed an increase in the N30 SEP peak amplitude, considering previous studies in subclinical subjects have consistently reported a decrease in N30 SEP peak amplitude after chiropractic spinal manipulation [32,36,39,40]. The increase observed in the present study may reflect an improvement in early sensorimotor function that is related to the observed increase in strength found in a recent study of chronic stroke survivors after a single session of chiropractic spinal manipulation [41]. In that study [41], Holt et al investigated the effect of chiropractic spinal manipulation on motor recovery in a chronic stroke population and found that, on average, plantarflexion muscle strength increased by approximately 64% after a single session of chiropractic care.…”

“…The chiropractic spinal manipulation and control interventions were similar to those used in previous studies [27,28,37,39,41] that have investigated the neurophysiological effects of chiropractic spinal adjustments. The same chiropractor performed the actual and control adjustments.…”

Immediate Impact of Extremity Manipulation on Dual Task Performance: A Randomized, Crossover Study

“…The prevailing thought on the neurophysiological impact of spinal/extremity manipulation is one of perceptual attunement brought about by mechanisms related to greater afferentation by peripheral receptors [28][29][30]; however, our consistent interaction effects suggest the modulation of visual perception may also be a possibility. Furthermore, the action capabilities of the participant are likely promoted by enhanced neural drive through supraspinal, spinal or extremity-based mechanisms [20,31,32].…”

Functional Connectivity Analysis on Resting-State Electroencephalography Signals Following Chiropractic Spinal Manipulation in Stroke Patients

“…Research suggests that SM alters mechanoreceptive input from the spine and that this in turn alters the way in which the brain processes, interprets, and integrates other interoceptive and exteroceptive information [ 5 ]. Previous studies have investigated the effect of SM on the function of the nervous system at different levels, for example motor output, sensory processing, functional performance, and sensorimotor integration [ 5 , 15 , 16 ]. These studies have contributed to the hypothesized model, described by Haavik and Murphy [ 5 ], which proposes potential mechanisms to explain how SM may alter bodily and CNS function [ 5 ].…”