The biceps brachii muscle and its distal insertion: observations of surgical and evolutionary relevance

Abstract

A sound understanding of the anatomy of the biceps brachii and possible anatomical variants is necessary to manage distal biceps injury. The present study was performed to define the anatomy of the biceps brachii with particular focus on the conformation of the distal biceps tendon, and its relationship of the two heads of the biceps brachii. Twenty cadaver specimens were dissected and both qualitative and quantitative observations were made of a series of features relating to the biceps muscle and its tendon. The investigation revealed anatomical variations including supernumerary heads (20%) and 'fusion' of the muscle proximal to tendon formation and a spiralling arrangement of the tendon in its approach to the radial tuberosity. The data from the present study was reviewed in the context of previous studies on the anatomy of this muscle and speculation on the evolutionary basis of the variations and their clinical implications are discussed.