C3 myotome controls which movement?

C3 myotome controls which movement?

• A. Neck flexion
• B. Lateral neck flexion
• C. Neck extension
• D. Shoulder abduction

Answer: (B)

The C3 myotome corresponds to lateral neck flexion—the head tilts toward one shoulder. This movement tests the nerve root distribution for C3, reflecting the neck muscles that bend the head to the side. Clinically, you’d assess by having the patient tilt their head sideways (or resist that movement) to gauge strength of this myotome. Other neck movements relate to different roots (neck flexion toward the chest is primarily C1–C2; neck extension involves upper cervical roots), while shoulder abduction relies mainly on C5. So lateral neck flexion is the best match for the C3 myotome.

The C3 myotome corresponds to lateral neck flexion—the head tilts toward one shoulder. This movement tests the nerve root distribution for C3, reflecting the neck muscles that bend the head to the side. Clinically, you’d assess by having the patient tilt their head sideways (or resist that movement) to gauge strength of this myotome. Other neck movements relate to different roots (neck flexion toward the chest is primarily C1–C2; neck extension involves upper cervical roots), while shoulder abduction relies mainly on C5. So lateral neck flexion is the best match for the C3 myotome.