Accessory muscles are relatively rare anatomic duplications of muscles that may appear anywhere in the muscular system. Though a wide array of accessory and supernumery muscles involving the ankle have been described in the literature, this is the first reported case we are aware of that features two accessory muscles. Accessory muscles are typically asymptomatic and often picked up as incidental findings but are important to be identified in the presence of chronic persistent ankle pain and the absence of other more common aetiologies.
During dissection an anomalous muscle was found on the medial aspect in the distal half of one left upper extremity. This muscle arose from the humerus between the m. coracobrachialis and the m. brachialis, passed obliquely across the front of the brachial artery and median nerve and blended with the common origin of the forearm flexor muscles. It does not appear to be an additional head of the biceps brachii or the brachialis muscles. The existence of this anomalous muscle should be kept in mind in a patient presenting with a high median nerve palsy together with symptoms of brachial artery compression.
Sternohyoid, sternothyroid, omohyoid, and thyrohyoid muscles are collectively known as infrahyoid muscles. These muscles frequently show variations in their attachments. Here, an extremely rare variant muscle belonging to this group has been presented. During cadaveric dissection for undergraduate medical students, an additional muscle was found between sternohyoid and superior belly of omohyoid muscles bilaterally in a male cadaver aged approximately 70 years. This muscle took its origin from posterior surface of the manubrium sterni, capsule of the sternoclavicular joint and the posterior surface of the medial part of the clavicle. It was inserted to the hyoid bone between the attachments of sternohyoid and superior belly of omohyoid muscles and was supplied by a branch of ansa cervicalis profunda. There is no report on such a muscle in the literature and it could be named as "sternocleidohyoid muscle". Knowledge of this muscle could be useful in neck surgeries.