Additional head of biceps brachii: a cadaveric study

ABSTRACT

Background: The biceps brachii is an important muscle of anterior compartment of arm. It shows frequent anatomic variability due to presence of supernumerary heads. Knowledge of the existence of the third head of biceps brachii is important for surgeons. Keeping this in mind a study was planned to see the incidence of additional head of biceps brachii in sample Indian population and to compare it with other racial groups.Methods: The study was carried out on 30 cadaveric upper limbs. The upper limbs were dissected and studied for the presence of additional head of biceps brachii. The attachment and nerve supply of the additional head was carefully observed, recorded and documented.Results: Out of 30 limbs which were dissected, additional head of biceps brachii was found only in two limbs. In both the cases the additional head was present only on the right side and arose from the anterior surface of humerus, superomedial to the origin of brachialis. The additional head fused with the common bulk of the muscle and was inserted into the radial tuberosity and bicipital aponeurosis. The extra heads of biceps brachii muscle received branches from musculocutaneous nerve.Conclusions: Biceps brachii is one of the commonest muscles showing variations. The additional head is not only of academic importance, but its knowledge also helps clinicians in managing fractures of humerus and nerve entrapment.