Am J Chin Med. 1979 Autumn; 7(3): 241-52.
The effects of stimulation of ear acupuncture points on the body's pain threshold.
Six ear acupuncture points, one non-acupuncture ear point, and the body locus Ho-Ku (LI-4) were electrically stimulated in order to compare the effects of stimulation on the body's pain threshold at selected loci on various points on the body by measurement with a radiation heat-type Pain Meter on 5 subjects. The ear points, with the exception of the non-acupuncture ear point, were found to be effective even in peripheral body regions in varying degrees. Ear stimulation did not increase the threshold as rapidly as Ho-Ku. In all cases where the pain threshold was raised, the effect persisted after electrical stimulation had stopped.