Dr. Hart's research

About this page

Studies below beginning with the one labeled as Study #1 are studies that Dr. Hart participated in, where he examined and adjusted the patients.  

The first study, Study #1, pertains to the outcome measure of athletic performance while the remaining studies have resting heart rate and heart rate variability as the outcome measures.  

Dr. Hart uses heart rate tests to determine how healthy his patient's nerve system is (rather than to diagnose heart problems, which he leaves to other clinicians).  Heart rate is a nerve system-based test which is why Dr. Hart thinks these tests are appropriate for his nerve-focused practice.

The heart rate tests are performed under the standard protocol of at least a 5 minute pre-test rest period. The tests help Dr. Hart: a) decide when a spinal adjustment is needed and b) whether the adjustment had a beneficial effect on the patient's nerve system. 

A healthier nerve system = a healthier patient. Healthier patients are patients who can better heal and maintain themselves. This is a central principle in Palmer (traditional) type chiropractic. 


More About Resting Heart (Pulse) Rate

There is an abundance of research conducted by others showing that a lower resting heart rate is healthier than a higher one. The adjacent figure, for example, is from a study published in the European Heart Journal showing that lower heart rate correlates with lower death rates.  Thus, resting heart rate (RHR) is a strong predictor of future health. 

Read more about resting heart rate at: https://www.health.harvard.edu/blog/resting-heart-rate-can-reflect-current-future-health-201606179806 

More About Heart Rate Variability

Another heart rate test used by Dr. Hart is heart rate variability (HRV). In a healthy nerve system, there is a bit of variation of time in between heart beats, e.g., 1 second between beats 1 and 2, 0.8 seconds between beats 2 and 3, 1.5 seconds between beats 3 and 4, and so on, even when sitting still. This variation occurs because of the constant changes that are occurring in the body, again, even when sitting still. This variability indicates that the nerve system (which controls heart rate) is adapting and ready for challenges. 

The adjacent figure (from Heartmath.org) shows two graphs. The upper graph shows heart rate (in beats per minute) while the lower graph shows time in between each beat occurring in the upper graph. Longer times between beats correspond with lower heart rate. The up and down rate change is a healthy finding and different than "skipped beats" or "irregular heart rate" which Dr. Hart defers to the medical doctor for these latter conditions.  

There is an abundance of research showing that higher HRV represents a healthier nerve system compared to lower HRV. This is the opposite of resting heart rate, where a lower number is healthier than a higher number.

The measure Dr. Hart focuses on in his HRV analysis is the root mean square of the successive differences in time between heart beats (rMSSD), measured in milliseconds. 

Learn more about HRV at: https://www.heartmath.org/articles-of-the-heart/the-math-of-heartmath/heart-rate-variability/

Introduction to the Studies

Studies 1-3 are already published in peer-reviewed science journals while the remaining studies are first published here, on Dr. Hart's research page. The adjacent image is the title page of Study # 3.

Patients in these studies gave their permission for Dr. Hart to publish their results.

The improvement in RHR and HRV in these studies indicate a  benefit patients receive at Hart Chiropractic above and beyond symptomatic relief.  

If you have a question about any of studies, contact Dr. Hart by email (at jhardc@yahoo.com) or by phone (at 350-2898). He will cheerfully receive any question or comment you might have.

Study #1: Improvement in athletic performance following chiropractic care

This study was conducted at Sherman College of Chiropractic in 1996 with Dr. Hart providing the chiropractic care. In the group that received his care, statistically significant improvements were observed in grip strength and long jump.  This indicates that Dr. Hart's spinal adjustments helped to improve athletic performance in these participants. Here is the citation with link to the journal:


Schwartzbauer J, Kolber J, Schwartzbauer M, Hart JF, Zhang J. Athletic performance and physiological measures in baseball players following upper cervical chiropractic care: a pilot study. Journal of Vertebral Subluxation Research (JVSR) 1997; 1(4):33-9. Journal: https://www.vertebralsubluxationresearch.com/2017/09/10/athletic-performance-and-physiological-measures-in-baseball-players-following-upper-cervical-chiropractic-care-a-pilot-study/

Study #2: Decreased (improved) resting heart rate following adjustment of spinal subluxation

This study was also done at Sherman College of Chiropractic, during 2013-2014. Participants who had atlas subluxation (misalignment of upper neck, bothering spinal nerves) were diagnosed and adjusted by Dr. Hart. Following the adjustment, resting heart rate decreased by a statistically significant amount.  This indicates that there was nerve system improvement following Dr. Hart's adjustment. Here is the citation: 

Hart J. Reduction of resting pulse rate following chiropractic adjustment of atlas subluxation. Annals of Vertebral Subluxation Research 2014; March 3: 16-21. Journal: 


Study #3: Improved resting heart rate following spinal adjustment at Hart Chiropractic

A study was recently published on patients at Hart Chiropractic comparing their resting pulse rates (RPR) before versus after Dr. Hart's spinal adjustments. The study found that patients experienced a benefit beyond symptomatic improvement, in the form of a statistically significant reduced (improved) RPR approximately three weeks following Dr. Hart's initial spinal adjustment, as shown in the adjacent figure. 

Here is the citation with link where the full paper is available for free: 

Hart J. Resting pulse rates under chiropractic care: A preliminary practice-based study. Internet Journal of Chiropractic 2018; 7(1): 1-5. Journal: http://ispub.com/IJCH/7/1/53087 

Study #4: Improvement in HRV at Hart Chiropractic

This case study involves a young adult male who Dr. Hart diagnosed as having an atlas subluxation (top neck bone slightly misaligned that was disturbing spinal nerve function). This diagnosis was made based on the low heart rate variability (HRV) readings (in the adjacent chart) along with slight misalignment of the atlas vertebra. 

As noted in the chart, the HRV readings were pretty much the same in the two readings just before the adjustment (marked in the chart as Pre 1 and Pre 2). Dr. Hart adjusted this patient's atlas on 10-25-18 and the HRV reading a few minutes after the adjustment (marked as "Post"in the chart) shows an obvious and substantial increase (improvement). 

Study #5 - Improvement in HRV at Hart Chiropractic

This case study involves an adult female who  was diagnosed by Dr. Hart as also having an atlas subluxation, evidenced by the low HRV readings along with slight misalignment of her atlas vertebra (top neck bone).

The Pre 1 and Pre 2 HRV readings in the adjacent chart were taken back-to-back just before the adjustment. Dr. Hart adjusted this patient's atlas on 11-15-18 and the HRV reading a few minutes afterwards showed a substantial increase (improvement) as observed in the adjacent chart. 

Improvement in the heart rate test indicates the patient's nerve system is healthier, which in turn will help the patient to better heal herself of what ails her. It's not a cure-all but still an important part of being healthy. It's kind of like a healthy diet or exercise which are also not a cure-all but still important parts of being healthy. 

Study #6 - Improvement in HRV at Hart Chiropractic

The patient in this case is an adult male who had an atlas subluxation on 11-19-18 that was adjusted by Dr. Hart. The two HRV readings prior to the adjustment on that visit were essentially the same (pre 1 and pre 2 in the adjacent chart). Following the adjustment though, there was a marked increase (improvement) in HRV, indicating a healthier nerve system for this patient.

Study #7 - Improvement in RHR and HRV at Hart Chiropractic

The patient in this case is an adult female who had two separate visits worth of exams, 1 day apart, prior to her spinal adjustment given by Dr. Hart for an atlas subluxation. 

The two visit approach was done because it was not clear that the patient had a chiropractic problem (subluxation) on the first visit. 

As shown in the adjacent chart, the resting heart rate (RHR) increased (worsened) from Visit 1 to Visit 2. This was the case for both RHR readings on Visit 2 (taken one right after the other). prior to the adjustment on Visit 2. 

Heart rate variability (HRV) was about the same from Visit 1 to Visit 2 pre 1, and then slightly improved on its own from pre 1 to pre 2 (one right after the other) on Visit 2. 

Following the adjustment on Visit 2, there was not much change in the post-adjustment readings for both tests (RHR and HRV) on that visit. However, on the next visit (Visit 3, eight days later), RHR had decreased (improved) to its lowest (best) number to date, to 61.4 beats per minute versus the 70-88 BPM range prior. 

The more impressive improvement though came with HRV - where it had been in the 20-38 millisecond (ms) range prior to the adjustment, it soared (improved) to 102.7 ms on Visit 3. This improvement was analyzed statistically to be an outlier, that is to say, it is an unusually high HRV number from a statistical standpoint compared to the other HRV numbers in the chart.

The improved heart rate tests indicate an improved health status of the patient's nerve system.

Study #8 - Improvement in HRV at Hart Chiropractic

This case was a house call for an adult male in December 2018.  All three readings are from the same visit. The two heart rate readings prior to the adjustment were essentially the same. Following the adjustment for atlas subluxation, in the post reading, resting heart rate (HR) continued to be about the same, with only slight improvement , as shown in the adjacent chart.  The big change came with improved heart rate variability (HRV). This indicates that the patient's central nerve system system is healthier compared to before the adjustment. A healthier nerve system = a healthier person. 

Study #9 - Improvement in RHR

In this case study of an adult male, all readings in the adjacent chart are from different days. The first two readings (10-24-18 and 10-26-18) are before the adjustment Dr. Hart gave on 10-26-18  (for atlas subluxation) while the remaining three are after the adjustment (10-31-18, 11-21-18, and 12-5-18). 

There was only a slight decrease (improvement) from the first to the second reading (before the adjustment) and the arrow indicates where in the chart the adjustment was given. 

The big decrease (improvement)  can be observed among the three readings after the adjustment compared to the two before the adjustment. 

With this number of readings, a statistical test can be done to estimate the probability that the decrease (improvement) in the post-adjustment readings happened by chance alone. An independent samples t test was performed by Dr. Hart. Although a t test is typically done with a larger set of numbers, it can nonetheless be used for small samples (Winter, 2013).

The t test revealed a statistically significant p-value of 0.04. This means that the improvement in the three post-adjustment readings probably did not happen by chance alone. 


Winter J. (2013). the student’s t-test with extremely small samples. Practical Assessment, Research & Evaluation. 18 (10): 1-12.

Study #10 - Improvement in RHR

In this case of an adult male, all RHR readings in the adjacent chart are from different days. Two adjustments (both for atlas sublxuation) were given by Dr. Hart, one at the first arrow (no adjustment on the two days preceding this first adjustment) and the other adjustment at the second arrow. The first adjustment did not have any effect, evidenced by no change in RHR. The second adjustment however, was followed by a substantial decrease (improvement) in RHR. In fact, a statistical analysis of all six readings indicated that this improved RHR reading was a statistical outlier - an unusually lower (better) reading. 

This case shows how Dr. Hart's analysis can differentiate between adjustments that don't versus do have a beneficial n effect on the patient's nerve system. 

Another interesting feature in this case is the already-low RHR readings prior to the adjustments. Normal for this patient, based on research by others, is 69 bpm. So one might think this patients RHR reading can't get much lower (better) - yet it did, from around a nice low RHR around 55.0 bpm down to a post-adjustment reading of 48.9 bpm.