Effects of ice massage of the head and spine on heart rate variability in healthy volunteers

Abstract

ObjectiveIce massage (IM) is one of the treatment procedures used in hydrotherapy. Though its various physiological/therapeutic effects have been reported, effects of IM of the head and spine on heart rate variability (HRV) have not been studied. Thus, this study evaluated the effects of IM of the head and spine on HRV in healthy volunteers. MethodsThirty subjects were randomly divided into 3 sessions: (1) IM, (2) tap water massage (TWM) and (3) prone rest (PR). Heart rate (HR) and HRV were assessed before and after each intervention session. ResultsA significant increase in the mean of the intervals between adjacent QRS complexes or the instantaneous HR (RRI), square root of mean of sum of squares of differences between adjacent normal to normal (NN) intervals (RMSSD), number of interval differences of successive NN intervals greater than 50 milliseconds (NN50), proportion derived by dividing NN50 by total number of NN intervals along with significant reduction in HR after IM session; significant increase in RRI along with significant reduction in HR after TWM, and a significant increase only in RMSSD after PR were observed. However, there was no significant difference between the sessions. ConclusionResults of this study suggest that 20 min of IM of the head and spine is effective in reducing HR and improving HRV through vagal dominance in healthy volunteers.