Which motor level is described as having hip flexors and adductors, knee extensors, and requires bracing and an AD, with reliance on arms?

• A. T12
• B. L2
• C. L3
• D. L4

Answer: (B)

Motor level is defined by the most caudal key muscle that has at least 3/5 strength, with all muscles above it also at least 3/5. Hip flexors (iliopsoas) and hip adductors are innervated at the L2 level, while knee extension (quadriceps) is primarily L3–L4. If a patient shows functional hip flexion and adduction but limited knee extension that necessitates braces and an assistive device, with substantial reliance on the arms for mobility, the motor level falls at L2. This pattern reflects preserved proximal hip function consistent with L2, but not enough distal knee extension to walk independently. Higher levels would imply additional distal motor control (knee extension at L3–L4 or ankle dorsiflexion at L4–L5), which would typically reduce the need for bracing and arm-dominant support.