The Autonomic Nervous System Activity and Osteopathic Manipulation

Abstract

The Osteopathic medical profession generally accepts that Osteopathic manual therapy (OMT) can be used to influence sympathovagal balance. However, there is little quantitative data evaluating this relationship. This study tested the hypothesis that cervical myofascial release increases vagal modulation of heart rate. The protocol lasted 30 minutes. Changes in body position were incorporated into the study to facilitate interpretation of autonomic tone measures. The protocol consisted of studying 17 human subjects in three positions; 10 min - horizontal, 10 min - 50 deg head-up, and 10 min - horizontal. Each subject was studied three times (control, sham, OMT) separated by at least one day. The OMT (cervical myofascial release) was applied while subjects were head-up. Sympathovagal balance was assessed by using spectral analysis of heart rate variability. In the control group, head-up tilt increased heart rate and the LF/HF ratio. The ratio increased from 1.45±0.23 (mean±SE) to 4.85±0.60 reflecting an increase in sympathetic and decrease in vagal tone. Sham treatment was not distinguishable from the control group. OMT caused a significant decrease in LH/HF ratio. The ratio decreased from 4.85±0.6 to 1.80±0.35. The results support the hypothesis that OMT can be used to modulate vagal tone. This study was approved by the institutional IRB; all subjects signed consent forms prior to participation in the study.