Jan 29, 2015Knees to Know
By Dr. Dawn Comstock
Each month, The Center for Injury Research and Policy at The Research Institute at Nationwide Children’s Hospital provides T&C with an inside look at their studies of high school athletics injuries. In this installment, Dawn Comstock, PhD, takes a look at knee injuries, examining gender-specific trends and breaking down each sport’s most common mechanisms of injury.
Athletes often devote hours to strengthening their legs and increasing knee flexibility, hoping not only to excel at their sport, but also prevent a season-ending knee injury. And athletes have good reason: knee injuries are one of the most common sports injuries, with U.S. doctors and surgeons treating over half a million high school student-athlete knee injuries every year. They are also among the most costly, and knee injuries account for almost half of all surgeries performed among high school athletes.
The National High School Sports-Related Injury Surveillance Study, in its third year of data collection, has found that high school athletes sustain approximately one knee injury in every 2,500 exposures. As one might expect, risk of knee injuries varies by sport and whether an athlete is practicing or competing. Here are some important facts on knee injury incidence:
• Knee injuries are three times more likely to occur during competition than practice. • Football players are at greatest risk for knee injury–on any given day, for every 460 athletes playing in a football game, one will sustain a knee injury. • Among girls, soccer players are at greatest risk for knee injury–on any given day, for every 850 female athletes playing in a soccer game, one will sustain a knee injury. • Girls participating in soccer, basketball, and softball are about 50 percent more likely to sustain knee injuries than boys playing these same sports.
Athletes dread knee injuries because they can signal a premature end to their season, particularly if a knee ligament is torn. The National High School Sports-Related Injury Surveillance Study has found that incomplete ligament tears (32 percent), contusions (15.2 percent), complete ligament tears (13.2 percent), and torn cartilage (eight percent) are the most common knee injuries. While 43 percent of athletes sustaining a knee injury are able to return to play that same week, 30 percent miss at least three weeks of play or are forced to discontinue the season. This rate is particularly high in girls’ basketball, where half of all injured players miss at least three weeks of play or are forced to discontinue the season. Following a knee injury, 25 percent of all girls and 12 percent of all boys require surgery. Overall, knee injuries commonly result from contact with another person (52 percent), no contact/overuse mechanisms (25 percent), and contact with playing surfaces (15 percent).
While knee injuries will never be completely eliminated, sports injury surveillance can help trainers and coaches develop sport-specific strategies to decrease their athletes’ risk for knee injuries. Here is what the latest research shows us regarding which activities are most commonly cited in a knee injury event:
Football
• Being tackled (27 percent) • Being blocked (19 percent) • Blocking (15 percent) • Tackling (13 percent)
Boys’ Soccer
• General play (23 percent) • Ball handling/dribbling (20 percent) • Receiving a slide tackle (10 percent)
Girls’ Soccer
• General play (23 percent) • Ball handling/dribbling (16 percent) • Defending (15 percent) • Chasing a loose ball (13 percent)
Girls’ Volleyball
• Digging (31 percent) • Blocking (16 percent) • Setting (15 percent)
Boys’ Basketball
• General play (24 percent) • Rebounding (21 percent) • Defending (15 percent) • Ball handling/dribbling (11 percent) • Chasing a loose ball (10 percent)
Girls’ Basketball
• General play (24 percent) • Defending (17 percent) • Rebounding (17 percent) • Ball handling/dribbling (16 percent)
Wrestling
• Takedown (57 percent) • Sparring (20 percent)
Baseball
• Fielding (32 percent) • Running bases (25 percent) • Sliding (20 percent) • Catching (10 percent)
Softball
• Sliding (29 percent) • Fielding (16 percent) • Batting (15 percent)
Dawn Comstock, PhD, is a principle investigator at the Center for Injury Research and Policy at The Research Institute at Nationwide Children’s Hospital. She is also an assistant professor at The Ohio State University in the College of Medicine and the College of Public Health. Her research interests include the epidemiology of sports, recreation, and leisure activity-related injuries among children and adolescents as well as the life-long health benefits associated with an active childhood. She can be reached at [email protected].
