Sympathetic and Parasympathetic Responses to Specific Diversified Adjustments to Chiropractic Vertebral Subluxations of the Cervical and Thoracic Spine
Written by Editor   
Sunday, February 07, 2016 12:00 AM

It appears that the area of the spine adjusted may have a direct effect on the autonomic nervous system. 


Chiropractors have suggested the positive effects of chiropractic adjustments on musculoskeletal and visceral health. Although there is a paucity of peer-reviewed studies in support of anecdotal perceptions, there are reports that provide evidence to support these perceptions. Moreover, although several studies have investigated chiropractic vertebral subluxation, spinal manipulative therapy, and cranial adjusting in relation to autonomic function, few studies have been done to link specific outcomes to specific levels adjusted.

Other studies have given mixed support to the view that the response of the autonomic nervous system is related to the region of the spine adjusted. Despite the limited evidence suggesting that changes in autonomic activity are consistently linked to chiropractic adjustments, autonomic mediated reflex responses including changes in heart rate, blood pressure (BP), pupillary diameter, and distal skin temperature, as well as, endocrine and immune system effects, have been clearly demonstrated. 

The aims of this study were to investigate the response of the autonomic nervous system based upon the area of the spine adjusted and to determine if a cervical adjustment elicits a parasympathetic response and if a thoracic adjustment elicits a sympathetic response.

Forty patients (25-55 years old) met inclusion criteria that consisted of normal blood pressure, no history of heart disease, and being asymptomatic. Patients were evaluated pre- and post-chiropractic adjustment for the following autonomic responses: blood pressure and pulse rate. Seven patients were measured for heart rate variability. The subjects received either a diversified cervical segment adjustment or a diversified thoracic segment adjustment.

Diastolic pressure (indicating a sympathetic response) dropped significantly postadjustment among those receiving cervical adjustments, accompanied by a moderate clinical effect (0.50). Pulse pressure increased significantly among those receiving cervical adjustments, accompanied by a large effect size (0.82). Although the decrease in pulse pressure for those receiving thoracic adjustments was not statistically significant, the decrease was accompanied by a moderate effect size (0.66).

It is preliminarily suggested that cervical adjustments may result in parasympathetic responses, whereas thoracic adjustments result in sympathetic responses. Furthermore, it appears that these responses may demonstrate the relationship of autonomic responses in association to the particular segment(s) adjusted.


Source:  http://chiro.org/wordpress/2015/11/sympathetic-and-parasympathetic-responses-to-specific-diversified-adjustments-to-chiropractic-vertebral-subluxations-of-the-cervical-and-thoracic-spine/