A muscle which allows you to turn your head to the left will not allow you to turn your head back to the center.

Question

Quizplus · Accepted Answer

The muscle that allows you to turn your head to the left is the left sternocleidomastoid muscle. This muscle originates from the sternum and clavicle and inserts into the mastoid process of the temporal bone. When this muscle contracts, it pulls the head to the left. However, this muscle does not have the ability to turn the head back to the center. The muscle that is responsible for turning the head back to the center is the right sternocleidomastoid muscle.

A Muscle Which Allows You to Turn Your Head to the Left