1. A series of 133 ankle sprains with an average follow-up of twenty-seven months has been studied for residual disability subsequent to the injury.
2. There was a 36 per cent. incidence of previous injury to the same ankle.
3. Residual ankle symptoms were found in 33 per cent. of the patients, and persistent abnormal changes of the ankle were found in 60 per cent.
4. The only statistically significant factor found among those who had chronic ankle symptoms was a high incidence of peroneal muscle weakness.