Anat Cell Biol.  2011 Sep;44(3):238-240. 10.5115/acb.2011.44.3.238.

Bilateral asymmetric supernumerary heads of biceps brachii

• Lee SE
• Jung C
• Ahn KY
• Nam KI

• KMID: 1447436
• DOI: http://doi.org/10.5115/acb.2011.44.3.238

Abstract

Anatomical variations of the biceps brachii have been described by various authors, but the occurrence of bilateral asymmetric supernumerary heads is rare and has not been reported. We found three accessory heads of the biceps brachii muscle on right arm and an anomalous third head of biceps brachii on left arm. The third, fourth, and fifth heads of right arm originated from the body of humerus at the insertion site of coracobrachialis and inserted into the distal part of biceps brachii short head in order. The third head of left arm originated from humerus at the insertion site of coracobrachialis and combined with the distal part of biceps brachii and continued to the proximal part of common biceps tendon. Understanding the existence of bilateral asymmetric supernumerary heads of biceps brachii may influence preoperative diagnosis and surgery on the upper limbs.

Keyword

Biceps brachii; Asymmetry; Supernumerary heads; Variation

MeSH Terms

Arm
Head
Humerus
Muscles
Tendons
Upper Extremity

Figure

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  Fig. 1 Anterior view of right and left upper arms. Note asymmetrical supernumerary heads on the biceps brachii muscle; five heads on the right side and three heads on the left side. Di, distal; L, lateral; LH, long head; Lt, left; M, medial; Pr, proximal; Rt, right; SH, short head.

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