At mid lumbar L3, which of the following is an expected hip function?

At mid lumbar L3, which of the following is an expected hip function?

• A. Hip Adduction
• B. Hip Abduction
• C. Knee Varus
• D. Ankle Inversion

Answer: (A)

Understanding motor function by spinal level helps explain which hip movements you’d expect at mid-lumbar L3. The hip adductors—like adductor longus, brevis, magnus, and gracilis—are innervated by the obturator nerve, which carries fibers from L2 through L4. At L3, those roots are intact enough to drive hip adduction, so bringing the thigh toward the midline is an expected action.

Hip abduction, by contrast, relies mainly on the gluteus medius and minimus via the superior gluteal nerve (primarily L4 to S1), a different nerve root range, so it’s not the characteristic function associated with L3. Knee varus involves knee joint mechanics rather than hip muscle action, and ankle inversion involves muscles in the lower leg and foot with different innervation. Therefore hip adduction best fits the expected hip function at mid-lumbar L3.