Median nerve and brachial artery entrapment in the abnormal brachialis muscle - A case report

Knowledge of variation in the pattern of muscle insertion and possible neutovascular entrapment is important for orthopedic surgeons, plastic surgeons and physiotherapists. We found a variation in the insertion pattern of brachialis and entrapped median nerve and brachial artery due to the superficial position of the muscle, in relation to the neurovascular bundle. The brachialis was found to have an additional thick slip from the distal third of the muscle. The accessory slip partly merged with the origin of superficial flexors of the forearm and partly inserted to the medial aspect of olecranon process. The median nerve and brachial artery passed under this additional slip of brachialis. The abnormality reported here might result in neurovascular compression symptoms in upper limb and some mechanical advantages or disadvantage in the flexion of elbow joint.