The shorter time frame is an approach commonly used in chiropractic research, in regard to: a) before and after care findings for HRV and pain, 8 b) correlation with health perception, 9 and c) correlation with area of the spine that was adjusted. Sessions for HRV testing are typically either 5 minutes or 24 hours. Both of these measures (SDNN and mean heart rate) are considered as ANS markers. 2 Another main measure in HRV is mean heart rate.

A higher SDNN value is considered healthier than a lower SDNN value. One of the main measures in HRV is the standard deviation of normal-to-normal beats (SDNN), 7 having a unit in milliseconds (ms), representing the amount of variability of the heart rate. One way to test a potentially useful option for assessing autonomic variability is to compare it to a gold standard for autonomic variability such as heart rate variability (HRV).

Thus, additional evidence-based options would seem helpful to increase feasibility in chiropractic practice for assessing ANS adaptability. The number of these options is currently limited. Many chiropractors who focus on vertebral subluxation may wish to choose from a variety of options for assessing ANS adaptability/variability. For example, higher variation in blood pressure has been correlated with atherosclerosis and diabetic nephropathy in patients with Type 2 Diabetes.

A higher amount of heart rate variability is neurologically healthier than lower heart rate variability in terms of various cardiological and noncardiological diseases. 5 Briefly, the concept is that variation in certain autonomic functions, such as heart rate, is considered to represent a healthy nervous system. 4 In chiropractic, neuro-adaptabilty is typically analyzed with pattern analysis. 3 In current day terminology, neurological adaptability, particularly in regard to the ANS is described by the complexity model as it is known in medicine. Stephenson advanced the idea that subluxation interferes with the body’s ability to adapt. One aspect of subluxation theory involves the potential effect of subluxation on the autonomic nervous system (ANS), the health of which can be assessed in terms of “autonomic variability” measures. The present study focuses on a potentially useful neurological predictor, if not also a useful outcome variable that may be related to putative subluxation.

Briefly, vertebral subluxation is theorized to consist of some type of minor biomechanical aberrancy between two vertebrae, resulting in some type of (and yet still-to-be defined) neurological disturbance. For purposes of this study, the “adjustable lesion” is referred to as vertebral subluxation since the author considers this to be a more familiar term within the profession. Others may prefer to call the target of chiropractic intervention a “functional articular lesion,” where the purpose of the intervention is to “produce (a) beneficial neurologic effect.” 1 In either case, a measurable neurological outcome of some type is presupposed. One approach in chiropractic care of patients pertains to the analysis and adjustment of vertebral subluxation, a condition with various theoretical underpinnings.

Pulse rate