What is a characteristic of the pawl lock with bail release in KAFOs?

• A. It is a free motion joint
• B. It uses a spring-loaded posterior lever to unlock the knee, may add bulk
• C. It locks the knee in extension permanently
• D. It prevents knee flexion in swing

Answer: (B)

The main idea is how a locking knee in a KAFO is released. A pawl lock uses a small pin (the pawl) that drops into notches on the knee mechanism to hold the knee in extension during stance, giving stability when bearing weight. The bail release is a lever placed on the back of the knee area that the user activates to free the pawl, allowing the knee to bend for swing. Because this mechanism and its lever live on the posterior aspect and include hardware to engage and release the lock, it can add bulk to the orthosis. It isn’t a free-motion joint by itself, and it isn’t designed to lock the knee permanently. Nor does it prevent knee flexion during swing when unlocked; the purpose of the release is to enable flexion for stepping.