Which is an action of the sternocleidomastoid?
A)contralateral rotation of the neck and head at the spinal joints
B)retraction (adduction)of the scapula at the scapulocostal joint
C)lateral rotation of the arm at the glenohumeral joint
D)ipsilateral rotation of the neck and head at the spinal joints

Question

Quizplus · Accepted Answer

The sternocleidomastoid muscle, when acting unilaterally, causes contralateral rotation of the neck and head at the spinal joints. This means that if the muscle on one side contracts, it turns the head to the opposite side.

Which Is an Action of the Sternocleidomastoid