An anatomical study of the third head of biceps brachii muscle and its innervations

Abstract

Introduction: Biceps brachii muscle is the double headed flexor muscle of anterior compartment of arm, showing most common anatomical variation. Objective: To study the morphological variation of biceps brachii muscle along with its innervations. Method: 42 upper extremities of 21 formalin fixed cadavers used during routine dissection in anatomy department of LMC were studied. Biceps brachii muscles were examined for their attachments, number of heads of origin, level of fusion of muscle bellies and innervations. Appropriate photographs were taken. Result: Out of 42 upper extremities of 21 cadavers third head of biceps brachii muscle was found in two right upper extremities (9.52%). One of the specimens had dual nerve supply from musculocutaneous and median nerve where as in another specimen third head was innervated only by musculocutaneous nerve. Conclusion: Knowledge of additional head of biceps brachii is important for surgery of the fracture of shaft of humerus.