A rare anomalous muscle in the popliteal region - a case report.

Anomalous muscles are rarely seen in the popliteal region of the lower limb. Some of them are harmless and go unnoticed and some create problems such as neuropathies. We report a novel case of an unusual additional muscle in this region. The additional muscle was closely associated with the short head of the biceps femoris muscle. It took its origin from the lower part of the lateral supracondylar line and the adjoining popliteal surface of the femur. The muscle was 10 cm in length, 1 cm in breadth and was fleshy throughout. It was oriented parallel to the medial side of the tendon of biceps femoris. It was inserted to the posterior aspect of the head of the fibula, medial to the insertion of the biceps femoris. The additional muscle derived its nerve supply from the sciatic nerve. The common peroneal nerve was closely related to the medial border of the additional muscle.