Effects of a 10-Minute Back Rub on Cardiovascular Responses in Healthy Subjects

This study determined the cardiovascular responses to a 10-minute back rub. Twelve healthy, college-age males and females (mean age = 22 years) volunteered to participate as subjects. Using an ABA design, the subjects tested for 10 minutes (Control #1) on a padded plinth lying on one side. During the Treatment period, the back rub was administered, which was followed by Control #2. Oxygen consumption (VO₂) was determined via the Medical Graphics CPX/D metabolic analyzer, which also estimated cardiac output (Q) using the CO₂ rebreathing (equilibrium) method. A repreated measures ANOVA was performed to statistically compare the cardiovascular responses across the three periods. The back rub, when compared to Control #1, had no significant effect on VO₂, but the central and peripheral components of VO₂ were changed. Cardiac output was decreased as a result of the decreased stroke volume (SV), as a function of the increased peripheral vascular resistance (PVR). We also found an increase in the extraction of oxygen (a-vO₂ diff) in the peripheral tissues. These results indicate that the VO₂ response during the back rub was achieved by reciprocal central (SV,Q) and peripheral (a-vO₂ diff) adjustemtns. Following the back rub, (i.e., Control #2 vs. Treatment), the decrease in VO₂, VCO₂, Ve, and a-vO₂ diff appears to indicate that it was effective in inducing relaxation. Since HR, SV, and Q were unchanged, the VO₂ response was result of the decreased a-vO₂ diff. Hence, the findings certain positive implications for the health care industry.