A rare variation of the longest striated muscle in humans

Abstract

Sartorius muscle is the longest skeletal muscle of the body. The muscle starts from the anterior superior iliac spine. Its tendon is attached to the anteromedial part of the proximal tibia bone and ends around the tuberosity of the tibia, together with the tendon of the gracilis and semitendinosus muscle and forms the pes anserinus (goose foot). In short, this muscle extends downward from the outer surface of the os coxae (usually similar to the letter s), from the ASIS towards the leg, as such it passes over the hip and knee joints and acts on two of the largest joints of the body. We observed an unusual biventeric variation of this muscle in routine dissection program of assistant education programme. In this biventeric variation we observed that there were two separate muscle bundles starting around anterior superior iliac spine. The lateral muscle bundle extended more linearly towards the medial edge of the patella and terminated around the tibial tuberosity. The distal tendon portion of this lateral part was closely associated with the patellofemoral ligament and medial collateral ligament before ending in the anterior margin of tibia. The medial muscle bundle also started from the anterior superior iliac spine but the extension of this bundle was similar to the classical sartorius muscle extension. The medial part was mainly associated with pes anserinus.