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Member Research & Reports

Member Research & Reports

Kentucky: What Factors Influence How Quickly High School Athletes Return to Play after Knee Injury?

Roughly 54 percent of all high school students in the United States – 7.8 million young people – participate in competitive sports. Every year, about 1.2 million of these teens are injured during sports participation. When an injury occurs, the first question asked by many players, along with their coaches and parents, is “when can I return to play?”

American football, a sport played by more than 1 million high school athletes in the United States, is a popular sport with a high injury rate. Among high school football players, knee injuries are the third most common injury. A team of investigators from the University of Kentucky College of Public Health and the Kentucky Injury Prevention and Research Center conducted a study to identify factors that influence return to play after knee injuries in high school football athletes – and whether return to play differs for varsity and non-varsity football players. Dr. Charlotte Baker is the lead author of the resulting publication, appearing in the Annals of Epidemiology. Co-authors are Dr. Steve Browning, Dr. Richard Charnigo, Dr. Terry Bunn, and Dr. Wayne Sanderson.

Although there is a wealth of data on the injuries that can occur during sports participation, information on the factors related to getting an athlete back on the field after an injury is limited – particularly for non-concussion injuries like those to the knee. Returning to play is a goal of most rehabilitation after sports injury and a major concern of most athletes. The time to return can be influenced by more than just the nature of the injury. Other factors include: the support of parents and coaches, the extent of medical care required to treat the injury, peers, and personal motivation. For young athletes, as well as their coaches and parents, it is important to identify what individual, sport-specific, and injury-specific risk factors influence the time to return to play after an injury to give all stakeholders better information to understand what to realistically expect after injury.

The investigators used academic year 2006-2007 through 2009-2010 data from the National High School Sports-Related Injury Surveillance Study. Polytomous logistic regression was used to assess factors influencing return to play. They found that following a knee injury, 31 percent of players returned either returned to play after more than 3 weeks, or did not return at all. After adjusting for injury severity, a difference in time to return to play persisted for injuries occurring in regular or post-season play compared to pre-season, as well as injuries to varsity players compared with non-varsity players.

The authors conclude that time in season, method of injury assessment, and the need for surgery were the main predictors of return to play for football athletes. They suggest that, as more factors were influential for varsity athletes than non-varsity athletes, future studies should separate the groups of athletes to better identify their specific factors for time to return.