After performing a history and physical examination, a decision must be made as to whether a radiograph should be obtained. The Ottawa Ankle Rules (OAR) provide a sensitive clinical decision rule for deciding when to obtain a radiograph. By selecting only those patients at risk for ankle fracture, the physician can avoid performing unnecessary radiographs.

The OAR state that an ankle radiograph series is only required when:

1. The patient is unable to bear weight (4 steps) both at the time of injury and at the time of evaluation OR
2. There is bone tenderness at the posterior edge of the distal 6cm or tip of the lateral or medial malleoli.

Furthermore, a foot radiograph series is required only when:

1. The patient is unable to bear weight (4 steps) both at the time of injury and at the time of evaluation OR
2. There is bone tenderness at the base of the fifth metatarsal or at the navicular bone.