Stimulation of the sympathetic nervous system will cause a reduction in the skin blood flow which can be detected by measuring the skin surface temperature. The purpose of this study was to see whether chiropractic adjustments could affect the activity of the sympathetic nervous system as reflected by changes in distal (fingertip) skin temperature.
Skin temperature on 196 subjects was measured before and within 10 seconds after a spinal adjustment. The difference between the pre- and post- temperatures was determined. The average fingertip temperature did not change when the spine was considered as an entire unit. However, when sympathetic and nonsympathetic regions were analyzed separately, we found significant differences in temperature response. The average temperature rose from 85.84 +/- 6.04 degrees F to 86.26 +/- 6.25 degrees F when C1-C7 and/or L4-L5 were adjusted (p < 0.001). When the area between T1-L3 was adjusted, however, the average temperature fell from 84.97 +/- 6.11 degrees F to 84.72 +/- 6.19 degrees F (p < 0.001).
These results illustrate that the blood flow through the fingertips can be affected by specific adjustments to the spine, and further, that the response varies, depending on the location of the adjustment. Thus, adjustments to the spine can, via stimulation of the nervous system, affect the physiology of tissues distant from the spine.