Detection of the Third Head of Gastrocnemius

Abstract

During a routine dissection for medical students in the Department of Anatomy, Faculty of Basic Medical Sciences, College of Health  Sciences of the Usmanu Danfodiyo University, Sokoto, the posterior aspect of the leg region of an adult male cadaver was observed to  have a third head of Gastrocnemius muscle unilaterally on the right leg. The third head of the muscle originated from the distal portion of  the right femur just above the lateral condyle between plantaris and the lateral head of Gastrocnemius, the third head was having a  short slender belly that descends down along the medial aspect of the medial head of the Gastrocnemius before tapering as a long  tendon that blends posteriorly with the calcaneal tendon. Upon tracing the muscle, it was confirmed to be a separate head with a distinct  origin and insertion independent of the usual two heads. This discovery of a third head of Gastrocnemius is certainly unusual and would  no doubt go a long way in drawing the attention of surgeons both in the interpretations of radiological images and the surgery itself.  Additionally, this discovery would add to the existing literature for the teaching of human anatomy generally.