A 16 yo guy is brought in ED by his mother after a scholar accident.
While he was running, he crashed.
My son has a sore ankle! Is it broken? Asks the mother seriously worried.
The ankle his slightly tumefied, there isn’t bone tenderness at the posterior edge or tips of either malleolus, neither there is pain during the pressure of the navicular bone or the base of the fifth metatarsal.
Are you able to take 4 steps? – asks the doctor.

Conclusion

If correctly performed (see the video) the Ottawa ankle rules have been shown to have high sensitivity, so if there is not an high pretest probability it rules out a fracture without any further test.
Their use leads to reduction of radiography, costs, and waiting time.

Bibliography

LM Bachmann
Accuracy of Ottawa ankle rules to exlude fractures of the ankle and mid-foot
Systematic review.
BMJ vol 326 22 feb 2003

IG Stiell
Decision rules for the use of radiography in acute ankle injuries
JAMA 1993 3 March vol 269 n9