The myotome that includes neck flexion and extension involves which vertebral levels?

The myotome that includes neck flexion and extension involves which vertebral levels?

• A. C1-C2
• B. C2-C3
• C. C5-C6
• D. C7-T1

Answer: (A)

The movement pattern here is governed by the cervical nerve roots that control the muscles of the neck. Neck flexion (nodding the head forward) and neck extension (tilting the head back) are primarily powered by muscles that receive innervation from the first two cervical nerve roots. Specifically, the deep neck flexors and the suboccipital muscles involved in extension are supplied by the C1–C2 myotome. That makes C1-C2 the myotome that includes both neck flexion and neck extension. Other level ranges map to different muscle groups and neck movements, so they don’t fit as the primary myotome for these motions. For example, C5-C6 relates to shoulder and elbow movements, and C7-T1 to different upper limb functions, not the neck.

The movement pattern here is governed by the cervical nerve roots that control the muscles of the neck. Neck flexion (nodding the head forward) and neck extension (tilting the head back) are primarily powered by muscles that receive innervation from the first two cervical nerve roots. Specifically, the deep neck flexors and the suboccipital muscles involved in extension are supplied by the C1–C2 myotome. That makes C1-C2 the myotome that includes both neck flexion and neck extension.

Other level ranges map to different muscle groups and neck movements, so they don’t fit as the primary myotome for these motions. For example, C5-C6 relates to shoulder and elbow movements, and C7-T1 to different upper limb functions, not the neck.