1. One of two thick muscles running from the sternum and clavicle to the mastoid and occipital bone; turns head obliquely to the opposite side; when acting together they flex the neck and extend the head
   "The sternocleidomastoid muscle is prominently visible when turning the head";
   - sternocleidomastoid, sternocleido mastoideus, musculus sternocleidomastoideus

Derived forms: sternocleidomastoid muscles

Type of: skeletal muscle, striated muscle

Part of: cervix, neck

Encyclopedia: Sternocleidomastoid muscle