A soft cast is a cast made from flexible fiberglass casting material and molded to the patient's injured limb. Soft casts are primarily used by athletes who have healed injuries that still need extra support when they're active. The cast is molded onto the limb for practice, then cut and removed at the end of the activity.
The only barrier in a soft cast is a stockinette. Since there is not any cotton padding under the fiberglass, before removing, a zipstick is placed between the cast and the skin to keep the saw from burning or otherwise causing the patient harm.
Once the cast is cut away, the rough edges are padded with moleskin to cover their rigid points. This is done to protect the wearer from hurting themselves, others or damaging their clothing. Wearers are also advised to use a strong file to smooth the edges of their cast.
A soft cast may also be used for immobilizing severe sprains, according to the University of Maryland Medical Center. To relieve the pressure of the sprain, hold the soft cast in place by tightly wrapping it with an ace bandage.