Background Athletics is one of the most popular global sports, but little is known of injury patterns among élite athletic athletes. Injury prevalence has been proposed to be the most valid measure of injury burden in sports where athletes practice long hours and are at risk for overuse problems.

Objective To compare two different indicators of injury prevalence in athletics as measures of the injury burden among adult and youth élite athletics athletes.

Design Cross-sectional epidemiological study using web-based data collection.

Setting Swedish élite youth (U17) and adult athletics athletes. Data were collected in April 2009.

Participants 278 youth and adult athletes (91%) submitted a web-based questionnaire from an eligible study population of 301 athletes.

Assessment of risk factors Athlete's sex, age and anatomical body regions were assessed as risk factors.

Main outcome measures 1-year prevalence of musculoskeletal injuries causing at least 3 weeks of partial or complete absence from practice and competition; point prevalence of musculoskeletal injury.

Results The 1-year injury prevalence was 43.6%. Among the age groups, the prevalence was 48.1% for adult and 37.1% for youth athletes. The point prevalence of injury was 36.2%, 38% among adult athletes and 33% among youth athletes. Female youth athletes had a tendency towards higher 1-year (p=0.06) and point (p=0.025) injury prevalence than male youth athletes. There was no sex difference in injury prevalence among the senior athletes. A majority of the injuries (74% 1-year prevalence; 78% point prevalence) reported by the athletes were located to the lower extremities.

Conclusion Using either the point or 1-year retrospective window definition of prevalence, currently approximately 4 out of 10 Swedish élite athletic athletes have injuries that interfere with their performance of sports activities. Most injuries are located to the lower extremities. Prospective epidemiological studies investigating individual risk factors for athletic injuries are warranted.