eng Science and Education Publishing American Journal of Medical Case Reports 2374-216X 2020-03-13 8 5 112 114 10.12691/ajmcr-8-5-1 AJMCR2020851 article John Hart Corresponding author: jhartdc@yahoo.com 1 Hart Chiropractic, Greenville, South Carolina Timing of an intervention is an important part of quality clinical care, including chiropractic care. In this case study the heart rate tests of resting heart rate (RHR) and heart rate variability (HRV) were used as outcome measure and for determining when to administer a chiropractic spinal adjustment. Optimal post-adjustment results were observed when the tests showed worse pre-adjustment values. Further application in other patients is planned. http://pubs.sciepub.com/ajmcr/8/5/1/ajmcr-8-5-1.pdf resting heart rate heart rate variability chiropractic