Prevalence of Fibularis Tertius Muscle in Southeastren Indian Population: a Surface Anatomical Study

Background:Fibularis tertius (FT) is a variant muscle of the anterior compartment of leg which involves in dorsiflexion and evertion of the foot. Literature shows that the reported prevalence of FT ranges from 49-100%. This study investigates the prevalence of FT in South-eastern population of India using surface anatomy techniques in living subjects and comparing it with the studies available in the literature.Material and Methods:Study included the evaluation of 195 subjects from Year 1 & 2 medical students (102 females and 93 males) which correspond to 390 feet in total. The average age of the sample was 17.9 years, with lower and upper limits of 17 and 20 years, respectively. The presence of FT was identified with a standard palpation technique that determines the presence of muscle on the basis of the progression tests called F1, F2, and F3.Results:The total FT prevalence was found to be 52% of the sample. On the right foot, FT was found to be 26.6% in males and 24.6% in females and on the left foot, it was 27.2% in males and 25.6% in females. FT palpation criterion showed 0 (zero) cases for F1, 31 cases for F2 and 172 cases for F3.Conclusions:This surface anatomical study reports for the first time the FT prevalence in South-eastren population of India. Further studies on prevalence of FT are needed to understand its role in biomechanics and reconstructive surgeries of the ankle and foot.