In briefSevere (grade 3) ankle sprains with lateral ligament disruption are common in both athletes and nonathletes. Inadequate treatment leads to chronic ankle instability. Twenty-six patients underwent a 3-week treatment program using an ankle-foot orthosis (AFO), followed by a 4-week rehabilitation program. Of these patients, 96% returned to activity without restriction in about 2 1/2 months. Advantages of the AFO include ease of application, patient comfort and convenience, early ambulation, access for therapy, and rapid return to sports with a stable, asymptomatic ankle.