Clinical and Functional Significance of Accessory Brachialis Muscle: An Unique Anatomical Variant

A thorough knowledge of the variations in the patterns of muscle insertion and the consequent neurovascular entrapment due to them is important for orthopedic and plastic surgeons. During routine dissection, we encountered a unique occurrence of an accessory brachialis muscle (acBr) blending with the medial aspect of bicipital aponeurosis in the cubital fossa. It also entrapped the median nerve and brachial artery due to its superficial position. The abnormality reported here might result in neurovascular compression symptoms in the upper limb and possible mechanical advantages or disadvantage in the flexion of elbow joint. To the best of our knowledge, the brachialis variant insertion we present here is rare in the list of its anomalies. We also discuss in this report the embryological background and the clinical application of the variation that can abet clinicians in evaluating symptoms involving the upper limb.