Bruising at the San Yin Jiao can be caused by prolonged standing, trauma, or yin and blood deficiency resulting in blockage of the spleen, kidney, and liver meridians. Sanyinjiao is located in the lower leg, behind the medial edge of the tibia, three inches straight up from the tip of the inner ankle, where the three yin meridians, i.e., the spleen meridian of the foot Taiyin, the kidney meridian of the foot Shaoyin and the liver meridian of the foot Syncopal meridian converge, which can be the main yin pathology, and the main lesions of the lower leg. If standing for a long time, trauma or yin deficiency, etc. caused by qi and blood stagnation (qi and blood transportation is not smooth, blocked stagnation), the meridians do not work, it can be reflected in the three yin jiao bruises, pressure and pain. Sanyinjiao is the meeting point of the three yin meridians of the foot, and lesions of the three yin meridians of the foot can be reflected here, with pressure and pain or bruises, etc. It can be used for the auxiliary diagnosis of menstrual irregularities, lower limb paralysis (lower limb weakness, numbness and pain) and other related diseases, and can also be used with other points for the treatment of diseases, which should be analyzed by comprehensive diagnosis in the clinic.