What motor level function has hip flexors and knee extensors and may need AFOs and AD vs HKAFOs and AD?

• A. T12
• B. L2
• C. L3
• D. L4

Answer: (C)

Understanding motor levels in pediatrics rehab hinges on which muscle groups (myotomes) still have strength. Hip flexion is mainly from the iliopsoas and is supplied by L2–L3; knee extension from the quadriceps is L3–L4. If the motor level is at L3, you have preserved hip flexion and knee extension, but weakness is likely present in muscles below that level, such as ankle dorsiflexors (L4) or foot intrinsics. That pattern means you can initiate hip movement and straighten the knee, but the ankle and foot control may be insufficient for a safe, efficient gait. To address that, an ankle–foot orthosis is commonly used to stabilize the ankle and foot, paired with an assistive device like a cane or walker. A hip–knee–ankle–foot orthosis is typically reserved for higher-level injuries where knee and hip control are also inadequate or trunk control is limited. So the motor level that best fits having hip flexors and knee extensors preserved—and potentially needing an AFO with AD rather than a more extensive HKAFO with AD—is L3.