Innervation of an aberrant digastric muscle in the posterior thigh: stratified relationships between branches of the inferior gluteal nerve.

During dissection of the gluteal region and the posterior thigh, an aberrant digastric muscle was observed on the right side of a 77-y-old Japanese male cadaver. This originated from the sacrotuberous ligament and inserted into the lateral surface of the long head of biceps femoris. Based on its innervation, this aberrant muscle may be homologous with the femorococcygeus.