Author(s): B. Meenakshi Parthasarathy1, Sowmya S2
Biceps brachii muscle is present in the anterior aspect of the arm. Variations are common in the number of heads, their origin, insertion and nerve supply. Morphological variations of biceps have great clinical significance for surgeons, orthopaedicians, anaesthetists, neurologists and anatomists. Additional head of the biceps brachii (AHBB) has been reported with a frequency of 1-25% in different population group. Aim of the present study is to know the incidence and morphology of AHBB.
Fifty upper limb specimens were looked for biceps brachii during routine dissection in Department of Anatomy, Bangalore Medical College and Research Institute for a period of 3 years.
In a 56-year-old male cadaver, two heads of biceps arose from its usual position along with which an additional head arose from anteromedial surface of shaft of the humerus in common with and distal to insertion of the coracobrachialis. The additional head fused with the common belly of the muscle, before the bicipital tendon and its aponeurosis. Bilaterally this additional head was supplied by a twig of the musculocutaneous nerve.
In the present study, 3-headed biceps brachii muscle was noticed in 4%. Knowledge of the morphological variations of biceps muscle provides better preoperative evaluation, safe surgical intervention within the arm and better postoperative outcomes.