Surface anatomy and prevalence of fibularis tertius muscle in a south-western Nigerian population

Fibularis tertius is a variant muscle of the leg that inserts in the foot. It has been implicated in providing clues to the evolution of upright posture in man. This work investigates the prevalence of fibularis tertius muscle in the African population, using south-western Nigeria as a sample population. The percentage prevalence of fibularis tertius muscle in the population studied is 63%, with higher prevalence in males compared to females. The muscle was however observed to present itself more on the right limb than on the left. Fifteen percent (15%) of the subjects had fibularis tertius muscle only on the right foot. Six percent (6%) had the muscle on the left foot only, 52% had it on both feet and 27% did not have the muscle on any of their foot. A unique surface positioning of the fibularis ter-tius tendon was also observed in all the subjectsstudied. These findings may provide contributions to the clinical evaluation of the muscle.