It is well known that an abdominal sign of painful groin indicates an appropriate condition for choosing the Kampo formulation tokishigyakukagoshuyushokyoto (TSG). This evidence was found by Keisetsu Otsuka in 1963. He thought that this sign is correlated with the liver meridian.
However, the pathophysiological background for this sign has been unknown. Recently, the author made clear that this sign disappears by acupunctural procedure at the Hikon (ExB4) meridian point. According to this clinical evidence, the author proposes a new hypothesis for this abdominal sign in that it closely relates to a homeostatic mechanism. In the cold environment, sympathetic drive to the femoral arteries occurs in order to guard from radiation heat loss in the lower extremities. This drive also causes a reduction of blood supply to the pelvic viscera. The acupunctural procedure at the Hikon (ExB4) meridian point may release both the induration of the iliocostal muscle and the contraction of IOM simultaneously. TGS disconnects the vicious cycle which exist between the pelvic viscera and sympathetic ganglion, and improves various signs that correlates with ischemia of the pelvic viscera.