Contraction of the right sternocleidomastoid muscle
A)acts antagonistically to the pectoralis major.
B)acts synergistically with the trapezius.
C)hyperextends the head.
D)rotates the head down and to the left.

Question

Quizplus · Accepted Answer

Contraction of the right sternocleidomastoid muscle rotates the head down and to the left. It works together with the left sternocleidomastoid muscle to flex the neck and rotate the head to the opposite side. Actions A and B are incorrect. Action C is opposite to the actual action of the sternocleidomastoid muscle.

Contraction of the Right Sternocleidomastoid Muscle