A clinical guideline used by physicians evaluating acute ankle sprains to determine if ankle radiographs are indicated. Films are obtained if there is pain or bone tenderness in the distal 6 cm of the posterior tibia or fibula or pain at the tip of the lateral or medial malleolus or inability to bear weight immediately after injury or upon first evaluation for four steps. Should not be used in pregnant women, children under six, and decreased mental status. Sensitivity is reported to be 99% with specificity around 50%.