Auricular acupressure at knee, shenmen, sympathetic, subcortex points increases skin temperature at knee joints: a before-after interventional pilot study

Abstract

Ear acupuncture at the knee, shenmen, sympathetic, subcortex points has been shown to reduce pain in pa-tients with knee osteoarthritis. However, the precise mechanism underlying this analgesic effect remains incompletely under-stood. Significant correlation between alterations in pressure pain thresholds and local perfusion has been reported during filiform needle acupuncture. This study investigated the change in microcirculation, as indicated by the skin temperature of the knee joint in healthy volunteers following ear acupuncture at the four aforementioned acupoints, to gain a better under-standing of this analgesic effect of ear acupuncture in the treatment of knee osteoarthritis. This is a before-and-after interventional study, included 30 healthy volunteers who were randomly assigned to two groups. Ear seeds were applied to the knee, shenmen, sympathetic, and subcortex points, with continuous pressure for three minutes to elicit the deqi sensation. One group underwent treatment on the left pinna, while the other received treatment on the right pinna. Skin temperature measurements were taken using the FLIR C5 Compact Thermal Camera at baseline and 30 minutes post-auricular acupressure (AA). Following AA applied to the right ear, there was a significant increase in skin temperature (p<0.05). In contrast, AA applied to the left ear did not result in significant changes in skin temperature (p>0.05). No adverse events were observed during the study. AA at the knee, shenmen, sympathetic, subcortex points increased the skin temperature of the knee joint.