C1-C2 myotome controls which movements?

C1-C2 myotome controls which movements?

• A. Neck flexion and extension
• B. Neck lateral flexion
• C. Shoulder shrug
• D. Scapular rotation

Answer: (A)

C1-C2 primarily controls movements of the head relative to the neck, specifically neck flexion (bringing the chin toward the chest) and neck extension (tilting the head backward). These actions are produced by the small, deep muscles at the top of the spine (the suboccipital group) innervated by the C1/C2 region. That’s why neck flexion and extension is the correct match. Lateral neck flexion involves lower cervical segments (like C3–C4), shoulder shrug relies on the trapezius with contributions from the spinal accessory nerve (and C3–C4), and scapular rotation involves other muscles (such as the serratus anterior and upper trapezius) with C5–C7 input.

C1-C2 primarily controls movements of the head relative to the neck, specifically neck flexion (bringing the chin toward the chest) and neck extension (tilting the head backward). These actions are produced by the small, deep muscles at the top of the spine (the suboccipital group) innervated by the C1/C2 region. That’s why neck flexion and extension is the correct match. Lateral neck flexion involves lower cervical segments (like C3–C4), shoulder shrug relies on the trapezius with contributions from the spinal accessory nerve (and C3–C4), and scapular rotation involves other muscles (such as the serratus anterior and upper trapezius) with C5–C7 input.