A Cadaveric Study of the Fibularis Tertius Muscle

Abstract

The Fibularis Tertius (formerly peroneous tertius) is occasionally absent in humans, but it is rarely found in other primates. The muscle is a small partially separated portion of the extensor digitorum longus as its tendon but has an important role in locomotion and in evolution of human beings. It supports and stabilizes the longitudinal arches of the foot while standing and locomotion during dipedalism. It particularly assists in everting the foot, which is characteristically a human movement. In this study, 104 legs were dissected from 52 cadavers. The muscle was unexpectedly absent in a large number of cadavers (26.92%). It was present in (73.08%) of cases.