Significance: If the removable brace is found to be at least as effective as the cast, this study has the potential to standardize the treatment of all low risk ankle injuries. Since these injuries can be reliably detected by physical examination, routine radiography of these injuries can be eliminated. These injuries could therefore be safely treated by primary physicians, thereby reducing the number of emergency department visits, obviating the need for orthopedic referral, or a return visit for cast removal. As a result, this study will provide critical information about the optimal treatment for the majority of ankle injuries in children from the perspective of clinical efficacy and health economics.