For 9-12-year-olds with DMD, how many hours per day should night splints or AFOs be worn?

• A. 12
• B. 8
• C. 4
• D. 2

Answer: (B)

The main idea is to preserve ankle range of motion and slow the development of a tight plantarflexor (equinus) contracture in Duchenne by using nocturnal orthoses. In this condition, the calf muscles and Achilles tendon often shorten as weakness progresses, making walking harder and increasing energy use. Wearing night splints or an AFO during sleep keeps the ankle gently in dorsiflexion, providing a steady stretch through the night that helps maintain length of the posterior calf muscles and plantarflexors. Eight hours aligns with a typical night’s sleep, giving enough time for a meaningful stretch without overdoing it or risking skin irritation. Shorter durations like four hours may not prevent contracture, while longer durations such as twelve hours can be impractical. So, about eight hours per night is the best target for this purpose.