Small but Viscious: The Subclavius Posticus Muscle/Pequeño pero Vicioso: El Musculo Subclavius Posticus

Accessory muscles of the neck are rare and are of clinical significance when present. During routine dissection of head and neck, two accessory muscles were found in the neck region of two cadavers, both male, one on the right and the other on the left. Both muscles took origin from the superior margin of the scapula and the insertion of the first muscle was to the clavicle, merging with subclavius and the second muscle got inserted to the first rib near the costochondral junction. This paper highlights the clinical significance and embryological aspects of such accessory muscles in the neck region. KEY WORDS: Subclavius posticus muscle; Variation; Thoracic outlet syndrome.