Which muscles act as agonists in right rotation of the neck?

• A. Left SCM, Left Scalenes, Left Trapezius, Right Levator Scapulae
• B. Right SCM, Right Scalenes, Right Trapezius, Left Levator Scapulae
• C. Pectoralis Major
• D. Latissimus Dorsi

Answer: (A)

Turning the head to the right is produced by muscles that act to rotate the cervical spine toward the right. The sternocleidomastoid on the left is the primary mover for this rotation because its unilateral contraction rotates the head to the opposite side. The scalene muscles on the left also contribute by guiding the motion and adding rotational influence at the cervical joints. The left trapezius helps stabilize the neck and supports the rotational action, enabling the SCM and scalenes to work effectively. On the right side, the levator scapulae can assist in this rotation when the scapula is stabilized, contributing to turning the head toward the right. Taken together, these muscles on the left and the right levator scapulae form the group that actively produces rightward neck rotation. The pectoralis major and latissimus dorsi move the shoulder girdle rather than the neck, so they don’t serve as primary contributors to neck rotation.