Single acupressure on ST36 does not modulate skin blood flow and sympathetic nerve activity during and after cold stimulation of the hand

Acupressure on ST36 (Zusanli), located on the lower leg, commonly used to optimize autonomic nerve activity and systemic blood flow in traditional Chinese medicine. However, its efficacy remains controversial. This study hypothesized that a single acupressure on ST36 attenuates sympathetic nerve activity and mitigate skin vasoconstriction in response to cold stimulation. Twelve participants received either 5-min acupressure or sham pressure in the right ST36; subsequently, their left hand was immersed in cold water (10°C) for 10 min. Heart rate (HR), arterial pressure, skin temperature, and blood flow in both fingers were monitored. Autonomic nerve activity was assessed by HR variability. Water immersion decreased skin temperature and blood flow in both fingers with an increase in arterial pressure. However, there were no differences in these values or HR variability between the acupressure and sham trials. Acupressure on ST36 affected neither sympathetic nerve activity nor skin vasoconstrictive response during cold-water immersion.