Ankle sprains are one of the most common injuries experienced by youths and adults involved in physical activity. (1,2) Ankle sprains account for 10% to 44% of injuries in physically active populations, (3-5) with 42% to 70% of these people having a history of at least 1 ankle sprain. (6,7) Thirty-two to 74% of patients with a previous ankle sprain report some type of chronic symptom, (8-11) and 32% to 47% report functional ankle instability (FAI; ie, the sense of giving way) at follow up. (8,9,11) Furthermore, approximately 6% of FAI patients remain occupationally limited, (12) with 13% to 15% being limited from 9 months to 6.5 years. (12-13) Based on these reports, it is clear that ankle sprains and FAI in particular are a significant health risk to the physically active population. With increasing government and societal emphasis on exercise and physical activity, it is reasonable to expect that the numbers will remain constant or increase as more people become physically active. Despite the effect of ankle sprains on the health of individual patients, to our knowledge the effect of sprains on health-related quality of life (HR-QOL) has not been examined. Using the National Center for Medical Rehabilitation Re search (14) disablement model for rehabilitation research, traditional rehabilitation researchers have focused on the disease or pathophysiology of injury (eg, proprioception or joint laxity) or the organ dysfunction (15) resulting from injury (eg, ankle weakness, impaired balance, range-of-motion loss). Recently, ankle instability researchers have moved further up the disablement continuum to include measures of functional limitation such as the Foot and Ankle Ability Measure (FAAM), (16) the Foot and Ankle Disability Index (FADI), (17) the FADI sport version, and the Cumberland Ankle Instability Tool (CAIT). (18) These measures assess a person's ability to perform common functional tasks, such as walking and going up stairs, and are described as condition specific but generic in that they assess overall joint function rather than a pathologic condition or organ dysfunction. (19) Regardless of the measure, these authors have shown that patients with FAI have more functional limitation than uninjured (UI) participants. What remains unknown is how FAI affects a person's HR-QOL.