Predicting Athletic Injury
Predicting Athletic Injury
Forewarned is forearmed.

This tried and true maxim is the impetus behind a new Baptist Sports Medicine study evaluating the efficacy of three screening tools in an effort to predict … and potentially prevent … common athletic injuries.

Trent Nessler, DPT, managing director of Baptist Sports Medicine and primary investigator for the study, said the research team would compare the Star Excursion Test, Functional Movement Screen and Drop Jump Landing Test to see which has a higher predictive value for athletic injury when used as a pre-assessment tool.

“They are functional screening tests,” he explained. “They are used at the professional level, but you don’t see them used very much at the college level nor at the high school level.”

Even for pro athletes, Nessler continued, utilizing the screens is a relatively new addition to pre-season physicals. For the Baptist study, data collection will center on younger athletes. High school participants are Hillsboro, Sycamore, White House, Lipscomb, Harpeth Hall, Ezell-Harding and St. Cecilia Academy. Three universities –– David Lipscomb, Trevecca Nazarene and Fisk ––are also participating.

While all athletes are required to undergo a physical, Nessler said the current focus is to identify existing orthopedic injuries or risk factors for catastrophic events such as a heart attack.

The three screening tests used in the study look at movement and balance, and each has been shown to offer warning signals for future problems.

Lauren Abramson, a Baptist Sports Medicine-certified athletic trainer assigned to Hillsboro High School, is collecting data from participating sites and doing all scoring for the study. At her site, she performed each of the three screens on approximately 18 athletes including male football players and female basketball and softball players.

“As the year goes by, and we get tracking information on injuries, then we will go back to what I just did (pre-assessment screens) and compare each test,” she said.

The Functional Movement Screen looks at seven different movements of an athlete –– hurdle step, in line lunge, shoulder mobility, push-up ability, trunk rotation, deep squat and an active straight leg raise. Athletes are scored from zero to three on each of the seven tests with a “three” being assigned if the movement is performed without any compensation.

“If the total score is below 14, they (athletes) are more likely to suffer an injury. What kind depends on where the deficit is and what the sport is,” Nessler said.

He added that a volleyball player with a low score might be more susceptible to an ACL rupture whereas a weightlifter might suffer from low back pain down the road.

The Star Excursion Test requires an athlete to stand on one leg in a stationary position while moving the opposite leg in a series of diagonal patterns. Examiners assess balance and the ability to maintain stability of the ankle, knee, hip and lumbar spine. Testing is done with each leg. Nessler explained that a 10 percent variance between the right and left leg is an indicator that the athlete is at increased risk to suffer a lower extremity injury.

The third screen, the Jump Drop Test, calls for the athlete to vertically jump off a 12-inch high box and land on both feet facing straight ahead. The test is both observed onsite and videotaped for later review.

“The way your bones and joints absorb force should be in a fairly predictable pattern,” Nessler explained, adding that ideally the knees should be pointing straight ahead at the conclusion of the jump.

“Internal rotation and adduction at the femur is predictive of ankle injuries, knee injuries and low back injuries,” he said.

Abramson added gender differences have appeared in the Jump Drop Test and noted female and male athletes tend to land very differently. Another mitigating factor at the high school level, she continued, is that some of the younger athletes have not yet finished growing.

There are various reasons why an athlete might score poorly on any of the given dynamic tests.

“Sometimes it is a learned process, and sometimes it’s a deficit or a flexibility issue,” Nessler pointed out.

The presumption is that by recognizing trouble spots, physical therapists and athletic trainers could use their knowledge of the biomechanics of different sports to create an individualized program to strengthen areas of weakness.

“If you address the abnormal movement patterns that make them more susceptible to injury, not only are you going to reduce injuries, but you’re going to increase athletic performance because the body becomes much more efficient at performing the task,” Nessler noted.

“For the athlete, it is for their wellbeing,” Abramson said. As a trainer, she continued, “My life gets easier. We are excited because that is what we live to do … we try to prevent injuries before they occur.”

While previous research indicates all three screens have predictive merit, several questions remain to be answered. Which one has the higher predictive value? Does the efficacy of the screen vary depending on the sport? Is one test better for female athletes versus their male counterparts?

When these questions have been answered, Nessler hopes the current athletic physical will be changed nationally to incorporate the appropriate screening measure.

“Once an athlete has gone through the screen, we can have our athletic trainers implement a prevention program that is specific to that individual’s needs to help reduce injury rates,” Nessler said.

Abramson added, the trainers are quick to tell athletes there is no way to guarantee they won’t ever face injury, but by proactively implementing strategies to strengthen deficits and break bad habits, the risk can be significantly reduced.

“I think down the line, this is really going to help the schools; it’s really going to help the kids; and it’s really going to help the coaching programs,” she said.

If one or more of the predictive screens help reduce injuries and enhance performance, the outcome should be a “win/win” any coach or athlete could appreciate.

Photo Notes:
Above left: Student athlete Dylan Jordan executes an in line lunge, included in the Functional Movement Screen, under the direction of Trent Nessler, DPT, managing director of Baptist Sports Medicine; (right) Jordan demonstrates the deep squat, which is also part of the Functional Movement Screen.

October 2007