Which motor level function has hip flexors and adductors, knee extensors, ankle dorsiflexors; still needs AFO bracing but requires less UE support?

• A. L3
• B. L4
• C. L5
• D. S1-S2

Answer: (B)

The idea here is to identify the motor level by looking at which key muscles are working and how strong they are, then connect that level to expected bracing needs and functional use.

If hip flexors and adductors (functions around L2–L3) are present, and knee extensors (around L3–L4) are present, the next caudal key muscle to show meaningful strength is the ankle dorsiflexors (around L4–L5). When the most caudal key muscle with at least functional strength is the dorsiflexors at the L4 level, that defines the motor level as L4, given that the more cephalad muscles (hip flexors/adductors and knee extensors) are functional enough to support higher-level movement.

At this level, you’d typically see enough knee and hip control to support standing and some ambulation, but dorsiflexion is still modest and may require assistance to prevent foot drop. That’s why an ankle-foot orthosis is still needed to maintain proper foot position during gait. The reason less assistance from the upper extremities is needed is because the lower-limb strength and control (especially knee extension and the ability to position the foot via dorsiflexion with the help of the brace) reduce the reliance on the arms for balance and support during standing and walking, compared with lower levels where the upper limbs are used more for stability.

So the described pattern best fits the motor level where dorsiflexors are the most caudal key muscles with functional strength—L4.