The sternocleidomastoid muscle is a prominent neck muscle that plays a critical role in the movement of the cervical spine and acts as a key palpable landmark for important structures. Typically, this muscle originates from two heads: one head from the sternum on the anterior portion of the manubrium and the other from the medial third of the clavicle. In some rare cases, supernumerary heads and variations in attachment can be observed. This case report presents a unique unilateral variation of the left sternocleidomastoid muscle in a 91-year-old male formalin-fixed donor, in which six heads of origin were identified.
A unilateral variation of the sternocleidomastoid muscle: a case report of 6 origins
Madeline M. Damjanovic1*, Leilanie G. Clayton2*, Isabella G. Damjanovic1*
1 University of Manitoba, Department of Human Anatomy and Cell Science, 745 Bannatyne Avenue, Winnipeg, Manitoba, Canada
2 McMaster University, Education Program in Anatomy, Department of Health Sciences, 1200 Main Street W, Hamilton, Ontario, Canada, L8N 3Z5
*All authors contributed equally to this work
SUMMARY
Eur. J. Anat.
, 30
(4):
501-
505
(2026)
ISSN 2340-311X (Online)
