Which option describes the Posterior leaf spring (PLS)?

Which option describes the Posterior leaf spring (PLS)?

• A. Spring assist (Klenzak housing)
• B. Toe-off AFO
• C. Adjustable positioning AFO worn at night
• D. Posterior leaf spring (PLS): Plastic AFO that inserts into the shoe. Widely used to prevent foot drop

Answer: (D)

The key idea here is a dynamic ankle–foot orthosis designed to assist dorsiflexion without locking the ankle rigidly. The Posterior leaf spring is a plastic AFO that sits inside the shoe and uses flexible leaf springs at the back of the ankle. As you swing the leg forward, the leaves store energy and then gently help lift the foot, improving toe clearance and reducing foot drop. Because it’s inside the shoe and provides a spring-like assist rather than rigid support, it allows more natural ankle motion and is particularly useful for mild to moderate dorsiflexor weakness. Other options describe different devices or configurations (spring-assisted joints, a different brand-style AFO, or a night-time adjustable orthosis) and don’t match this posterior-leaf-spring description.

The key idea here is a dynamic ankle–foot orthosis designed to assist dorsiflexion without locking the ankle rigidly. The Posterior leaf spring is a plastic AFO that sits inside the shoe and uses flexible leaf springs at the back of the ankle. As you swing the leg forward, the leaves store energy and then gently help lift the foot, improving toe clearance and reducing foot drop. Because it’s inside the shoe and provides a spring-like assist rather than rigid support, it allows more natural ankle motion and is particularly useful for mild to moderate dorsiflexor weakness. Other options describe different devices or configurations (spring-assisted joints, a different brand-style AFO, or a night-time adjustable orthosis) and don’t match this posterior-leaf-spring description.