A brace can be a helpful tool to wear if you have sprained your ankle. An ankle brace will support your ankle when you walk and your foot flexes. An ankle brace can help prevent you from spraining your ankle again. The brace should support the outside and inside of your ankle, preventing the rolling motion that is often the cause of a sprained ankle. The decision to wear a brace can be left up to the comfort of whomever has to wear it.
(This answer provided for NATA by the Eastern University Athletic Training Education Program.)