Which muscles act as agonists in neck extension?

• A. SCM and Scalenes
• B. Trapezius and Levator Scapulae
• C. Latissimus Dorsi
• D. Pectoralis Major

Answer: (B)

Neck extension is produced by muscles on the back of the neck that pull the head backward, and it works best when the shoulder girdle is stabilized. The trapezius, especially when both sides contract to hold the shoulder region in place, provides a posterior pull that helps extend the neck. The levator scapulae, likewise, can assist in this movement when the scapula is fixed, contributing to a backward pull on the cervical spine. Together, they act as agonists for neck extension by supporting the head’s backward movement through their effects on the scapular region and cervical attachments. In contrast, the muscles that primarily flex or rotate the neck (like the sternocleidomastoid and scalenes) are not helping with extension, and muscles that mainly move the shoulder girdle or trunk (latissimus dorsi, pectoralis major) don’t serve as primary neck extensors.