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 / or 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.
Is it a coincidence that someone with the name Hart uses heart rate tests? Probably. At any rate (pun intended), the tests help to improve the quality of care that Dr. Hart provides.
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 and Heart Rate Variability
Dr. Hart uses these tests to check the health of the autonomic nervous system (ANS). The word autonomic looks and sounds like the word automatic and maybe this is one way to remember what the ANS does - it pretty much automatically controls so many vital functions in the body, such as heart rate and digestion. As noted in the Encyclopedia, the ANS is the part of the nerve system that "controls and regulates the internal organs without any conscious recognition or effort." (Learn more at: https://www.britannica.com/science/autonomic-nervous-system )
Resting heart 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. Learn more about RHR at: https://www.health.harvard.edu/blog/resting-heart-rate-can-reflect-current-future-health-201606179806
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 physiological changes occurring in the body. 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.
The adjacent figure illustrates the dual nerve supply that governs heart rate. In a healthy nerve system, there is a fluctuation between slower and faster heart rates from moment-to-moment, even when sitting still. A lack of fluctuation indicates a nerve system (ANS) that is disturbed. Dr. Hart uses this information to help him decide when his patient needs a spinal adjustment.
There is an abundance of research also for HRV, 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. Learn more about HRV at: https://www.heartmath.org/articles-of-the-heart/the-math-of-heartmath/heart-rate-variability/
The adjacent figure is from another study that compared HRV in two groups: a non-hypertensive group (N-HP) versus a hypertensive group (HP). Compared to the hypertensive group, the non-hypertensive group had a higher (better) HRV (p < 0.05). The chart is from:
Yu Y, et al. Value of assessing autonomic nervous function by heart rate variability and heart rate turbulence in hypertensive patients. International Journal of Hypertension. 2018. https://doi.org/10.1155/2018/4067601
Studies 1, 2, 3, 11 and 13 are published in peer-reviewed science journals while the remaining studies are published here on this research page.
Patients in all studies gave their permission for Dr. Hart to publish their results (anonymously).
The improvement in RHR and HRV in these studies indicate a benefit patients receive at Hart Chiropractic above and beyond symptomatic relief. This benefit is in the form of improved nervous system function. This is important because the nervous system controls so many other functions in the body.
If you have a question about any of these studies, contact Dr. Hart by email (at email@example.com) or by phone (at 350-2898).
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/
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:
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
More chiropractic research in Greenville.
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).
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.
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.
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.
The improved heart rate tests indicate an improved health status of the patient's nerve system.
Further evidence that the adjustment was the cause of the improvement, the improved post-adjustment HRV on Visit 3 was statistically significant compared to the average of all the readings (p < 0.05).
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 is healthier compared to before the adjustment. A healthier nerve system = a healthier person.
Further evidence that the adjustment was the cause of the improvement, the improved post-adjustment HRV was statistically significant compared to the average of all three readings (two pre's and one post, p < 0.05).
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.
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.
Dr. Hart recently had a paper published in the peer-reviewed science journal, the Internet Journal of Neurology. The study involved a group of patients he adjusted and measured with the nerve test heart rate variability. (HRV) Average HRV improved following adjustment and the change was statistically significant (p = 0.02). Here is the citation and link where the full paper is freely available:
Hart J. Heart rate variability following spinal adjustment: A practice-based study. Internet Journal of Neurology 2019; 21(1). Journal: http://ispub.com/IJN/21/1/53953
Occasionally we see patients who do not need an adjustment. This is an adult male who showed borderline readings for RHR and HRV on the first visit. At Hart Chiropractic in such cases the patient is asked to come back for a second visit to compare with the first in order to better determine whether an adjustment is indicated. The second visit showed improved readings, where RHR decreased (blue line in adjacent chart) and HRV increased (red line). The patient was told he did not need an adjustment but instructed to get checked periodically to see if his good neurological health continues.
Dr. Hart has come up with a method to statistically analyze heart rate variability data for an individual patient during a single office visit. This is a new "thing" since statistical analysis in healthcare research is typically reserved for groups of patients rather than for an individual patient. The main benefit for the new approach is that Dr. Hart can see immediately if the HRV change happened by chance alone or whether it was due to his spinal adjustment. Here is the citation where the full paper is freely available via Open Access:
Hart J. Improvement in heart rate variability following spinal adjustment: A case study in statistical methodology for a single office visit. International Journal of Statistics in Medical Research 2019; 8:17-22. Journal: https://lifescienceglobal.com/journals/international-journal-of-statistics-in-medical-research/volume-8/91-abstract/ijsmr/3575-abstract-improvement-in-heart-rate-variability-following-spinal-adjustment-a-case-study-in-statistical-methodology-for-a-single-office-visit