Which sequence correctly matches nerve roots to their corresponding movements (L4, L5, S1)?

Which sequence correctly matches nerve roots to their corresponding movements (L4, L5, S1)?

• A. L4 dorsiflexion; L5 great toe extension; S1 plantar flexion
• B. L4 plantar flexion; L5 dorsiflexion; S1 great toe extension
• C. L4 knee extension; L5 ankle eversion; S1 toe flexion
• D. L4 dorsiflexion; L5 plantar flexion; S1 great toe extension

Answer: (A)

In neurologic assessment of the lower limb, each nerve root has a primary movement it controls. For these roots, the standard myotome map links L4 to ankle dorsiflexion (lifting the foot up toward the shin), L5 to great toe extension (lifting the big toe up), and S1 to plantar flexion (standing on tiptoes). This makes the sequence L4 dorsiflexion, L5 great toe extension, and S1 plantar flexion the correct match. The other options would swap these movements in a way that doesn’t align with the typical myotome pattern.

In neurologic assessment of the lower limb, each nerve root has a primary movement it controls. For these roots, the standard myotome map links L4 to ankle dorsiflexion (lifting the foot up toward the shin), L5 to great toe extension (lifting the big toe up), and S1 to plantar flexion (standing on tiptoes). This makes the sequence L4 dorsiflexion, L5 great toe extension, and S1 plantar flexion the correct match. The other options would swap these movements in a way that doesn’t align with the typical myotome pattern.