Which of the following is an indication for using a knee-ankle-foot orthosis (KAFO)?

• A. Medial and lateral instability of the knee
• B. Weak quadriceps with grade 5 strength
• C. Knee effusion with swelling
• D. Normal knee function

Answer: (A)

KAFOs are used when the knee cannot stay stable during standing and walking because of ligament laxity or neuromuscular weakness. Medial and lateral instability means the knee tends to buckle inward or outward with weight bearing. A KAFO provides rigid control from the thigh to the ankle and can lock the knee, preventing that side-to-side collapse and keeping the knee extended in stance. This stabilization makes walking safer and easier, which is particularly important for individuals with conditions like spina bifida where knee control can be compromised.

The other scenarios don’t fit as indications because a knee effusion/swelling is an inflammatory issue that isn’t resolved by bracing, normal knee function doesn’t require support, and a quadriceps strength described as grade 5 indicates normal strength, which wouldn’t necessitate a KAFO.