OTC TruSoft Night Splint For Plantar FasciitisWhen worn as intended it will prevent the plantar fascia from contracting while in the prone or supine (sleeping) position. The night splint holds the ankle and forefoot in a position of slight dorsiflexion and thus prevents the plantar fascia from contracting, which causes pain. Non elastic encircling strap keeps sock in place on leg. Non abrasive fastening material throughout. Extra soft sock for comfortable wear during sleep. Non elastic toe strap