The C7 myotome corresponds to which action?

• A. Ankle dorsiflexion
• B. Hip flexion
• C. Elbow extension and wrist flexion
• D. Finger flexion and thumb extension

Answer: (C)

Testing a myotome links a spinal nerve root to the muscle actions it controls. The C7 root mainly drives elbow extension (through the triceps) and wrist flexion (via wrist flexor muscles). So when you assess these movements—elbow extending against resistance and wrist bending toward the palm—you’re evaluating C7 function. If these actions are weak while other areas are normal, it points to C7 involvement. In contrast, ankle dorsiflexion is controlled mainly by lower roots (L4–L5), hip flexion by L2–L3, and finger flexion plus thumb extension involve C8–T1, so they don’t reflect the C7 myotome.