According to KidsHealth, a walking cast is an additional piece placed on an cast's heel that allows the patient to walk while still encased. KidsHealth states that walking casts must be thoroughly dry prior to use.
The American Academy of Orthopaedic Surgeons reports that drying time for a fiberglass cast is one hour, but a plaster cast takes two or three days to set. Casts support and keep bones in place during healing while also minimizing swelling, pain and muscle spasms.
Besides being used for fractures, the Wake Forest Baptist Medical Center indicates walking casts are appropriate for some cases of plantar fasciitis. California's Oakland Bone and Joint Specialists sometimes recommend walking casts for Achilles tendonitis.