Three Headed Biceps Brachii Muscle

During our routine dissection studies, we encountered an accessory head of biceps brachii in the left upper extremity of a 73-year-old formalin-fixed male cadaver. The other two heads of the muscle and other arm muscles were as usual. Humeral accessory head of biceps brachii muscle was classified according to the originated location of the head of biceps brachii muscle by some researchers as infero-medial humeral, superior humeral and inferolateral humeral head. In this case, the accessory head was originated from middle third of the humerus, superior and medial to the origin of brachialis muscle and inserted to the common tendon of biceps brachii. In the literature, this head was named as infero-medial humeral head and its incidence changes between 7.7-12% according to ethnicity. In Turkish population, its incidence changes between 2.5-6.15%. We think that knowledge of this type of the variation is important for prevention of possible surgical complications and diagnostic procedures.