An unusual variant of the levator claviculae muscle encountered in exploration of the brachial plexus.

The levator claviculae muscle is a vestigal muscle which occurs in less than 2% of humans. The embryological origin of this muscle is controversial. We report a case in which an unusual variant of this muscle was encountered during exploratory surgery following a brachial plexus injury. The anatomical findings in this case suggest that this muscle may arise from either the sternocleidomastoid or trapezius muscles or from the primordial ventrolateral musculature.