Osteopathic Cranial Manipulation and its Possible Application in Managing Hypertension for the Optimization of Care
Authors: Jackson Stephanie , Chung Tsz Chun , Arellano Alyssa , Keane James , Goldstein Leonard B. 
Published: November 2024

Context: Approximately 50% of US adults suffer from hypertension, with over 75% inadequately controlled. The baroreceptor reflex elicits vagal stimulation, reducing heart rate and blood pressure. Non-invasive osteopathic cranial manipulation (OCM), including occipito-atlantal (OA) release, may enhance vagal tone. This literature review examines the potential efficacy of OCM in optimizing hypertension management by augmenting vagal tone and subsequently reducing blood pressure.
Objective: To determine whether osteopathic cranial manipulation (OCM) may be utilized for blood pressure reduction and hypertension management via vagal nerve stimulation affecting the baroreceptor reflex. Specifically, we aim to investigate the effects occipito-atlantal (OA) release has on vagal tone and determine whether it has reasonable applications within hypertensive conditions.
Methods: Our group searched for credible literature sources on Still OneSearch, DynaMed, Google Scholar, PubMed, MEDLINE, and National Institutes of Health (NIH) online databases as well as the following journals: Frontiers in Neuroscience, Journal of Alternative and Complementary Medicine, and Medicines. The search strategy included keywords or a combination of keywords such as “hypertension or high blood pressure”, “baroreceptor reflex”, “vagal nerve stimulation”, and “osteopathy or osteopathic manual therapy or OMT or manual therapy or osteopathic medicine or osteopathic treatment” to discover related articles. Filters for peer reviewed sources with access to full text and publication dates between 2010 - 2023 were applied to our search, narrowing the results to only the most up-to-date information. Once studies of interest were selected, the articles were read and analyzed with pertinent components referenced throughout our literature review in accordance with AMA citation format. Altogether, this project demonstrates osteopathic significance because it emphasizes the value of osteopathic cranial manipulation (OCM), spreads awareness of Sutherland’s philosophies, and underscores the possibility of OCM applications in the treatment of hypertension. Furthermore, it describes how OCM can be used in combination with or as a safer alternative to managing hypertensive conditions, thus creating more options for providing quality healthcare.
Results: This literature review sought to examine the potential efficacy of HTN management through the utilization of osteopathic cranial manipulation. In the clinical and preclinical studies of vagus nerve stimulation (VNS) therapy, it was found that a 4-week-long VNS therapy significantly decreased mean arterial pressure and the number of arrhythmic episodes in rats with salt-induced hypertension, with a potential side effect being bradycardia due to asystole. In theory, by initiating manual biomechanical alignment in the OA joint would improve vagus nerve function and thus increase parasympathetic function to the heart to reduce atrial contraction, comparable to VNS. A study examining 19 healthy, young adults who underwent cervical OMT and had their heart rates measured pre- and post-electrocardiography, revealed moderate enhancement of parasympathetic HR control. In another study of 63 subjects with hypertension who were treated with OMT for 1 year, it was found that their systolic blood pressure improved significantly. In a randomized controlled study, a combination of kneading and stretching of soft tissues and suboccipital decompression, there is an increase of 15% of parasympathetic modulation of heart rate with p=0.02.
Conclusion: Research agrees that the instigation of parasympathetic activity through vagal nerve stimulation adjusts heart rate in the response to baroreceptors that detect arterial pressure changes within the heart. Giles et al demonstrated a positive relationship between the effects of OMT and acute heart rate variability. However, the relationship between heart rate and vagal activity is not linear, and has been previously difficult to clearly denote. Overall, this literature review demonstrates the significant impact hypertension has on society and the need for alternative treatments. In research conducted by Giles et al, OMT was proven to have an effect on heart rate variability in health individuals and although the research was not conducted on patients with somatic dysfunction, the data suggests that the effect on heart rate via OMT is measurable and definitive. This lends to a promising advancement in the relationship between OMT and heart rate in a diseased population. Assessment of this change in the frequency domain of autonomic control suggests necessary evaluation of the shift in sympathetic to parasympathetic states within chronic HTN patients. In evaluation of current research, it is not possible to draw a definitive conclusion about the effectiveness of OCM on the management of HTN. Future research should be conducted in the evaluation of OCM and the specific types of techniques that offer the greatest effect on both heart rate and blood pressure. Ideally these projects would determine the effectiveness of OCM through a dedicated, well-designed, controlled and blinded outcome study for the evaluation of statistically significant results. The data that would be extracted from these future studies could have profound impacts on the integration of OMT into the scheme of hypertension management and inform policy changes to enable it as a viable tool for treatment.