Which option describes the Posterior leaf spring (PLS) usage?

Which option describes the Posterior leaf spring (PLS) usage?

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

Answer: (D)

The key idea here is a dynamic, foot-drop–preventing ankle-foot orthosis that sits inside the shoe. A posterior leaf spring is a thin, flexible plastic component positioned at the back of the orthosis. As the foot moves from mid to late stance into swing, the leaf stores energy when the ankle goes into plantarflexion and then releases it to assist dorsiflexion, helping lift the front of the foot for better toe clearance. Because it’s a lightweight, inside-the-shoe design, it provides this assist without rigidly immobilizing the ankle, making it a common choice for patients with mild to moderate dorsiflexor weakness. Other options describe different devices or uses: a spring-assisted unit with a Klenzak housing works differently and isn't the posterior leaf spring design; a Toe-off AFO is another dynamic option but not the classic posterior leaf spring; an adjustable positioning AFO worn at night is intended for positioning rather than providing daytime dorsiflexion support.

The key idea here is a dynamic, foot-drop–preventing ankle-foot orthosis that sits inside the shoe. A posterior leaf spring is a thin, flexible plastic component positioned at the back of the orthosis. As the foot moves from mid to late stance into swing, the leaf stores energy when the ankle goes into plantarflexion and then releases it to assist dorsiflexion, helping lift the front of the foot for better toe clearance. Because it’s a lightweight, inside-the-shoe design, it provides this assist without rigidly immobilizing the ankle, making it a common choice for patients with mild to moderate dorsiflexor weakness.

Other options describe different devices or uses: a spring-assisted unit with a Klenzak housing works differently and isn't the posterior leaf spring design; a Toe-off AFO is another dynamic option but not the classic posterior leaf spring; an adjustable positioning AFO worn at night is intended for positioning rather than providing daytime dorsiflexion support.