Which motor level function has hip flexors, adductors, knee extensors, ankle dorsiflexors, and ankle plantarflexors, with toe extension and toe flexion?

• A. L4
• B. L5
• C. T12
• D. S1-S2

Answer: (D)

The main idea here is identifying the motor level as the most caudal myotome that still shows usable strength, with all levels above it assumed to be at least as strong. Looking at the muscles listed:

• Hip flexors and adductors are powered mainly by L2–L3.

• Knee extensors by L3–L4.

• Ankle dorsiflexors by L4–L5.

• Toe extension by L5.

• Ankle plantarflexors and toe flexors by S1–S2.

Among these, the lowest (most caudal) myotome that typically demonstrates real strength in this pattern is the sacral level, S1–S2, which includes ankle plantarflexion and toe flexion. Even if more proximal muscles (hip flexors, knee extensors) are present at higher levels, the motor level is defined by the most caudal intact function, so S1–S2 is identified as the motor level in this scenario.