March 2017

Injury risk gets clinical: Studies support value of inexpensive tests

In the moment: Sports medicine 498464522

By Jordana Bieze Foster

Clinicians don’t often have expensive biomechanical testing equipment to improve their assessment of injury risk in athletes, but a growing body of research—including several studies presented in February at the American Physical Therapy Association’s Combined Sections meeting in San Antonio, TX—suggests standard clinical tests can help fill that void.

Aspects of the triple-hop-for-distance test, for example, are significant factors differentiating young athletes at high risk of a second anterior cruciate ligament (ACL) injury from those at low risk, according to research from Cincinnati Children’s Hospital in Ohio presented at the meeting.

In 120 athletes (105 girls; mean age 16.7 years) who had under­gone functional testing when they were cleared to return to sports after an initial ACL injury and reconstruction, the investigators found those who went on to suffer a second ACL injury within two years typically matched one of two high-risk profiles.

Both high-risk profiles included age younger than 19 years. Those who fit the first profile had a triple-hop distance on the involved limb between 1.34 and 1.9 times their height and triple hop limb symmetry of less than 98.5%. Those who fit the second profile were female and had a triple-hop distance more than 1.34 times their height, triple-hop symmetry greater than 98.5%, and high knee-related confidence.

In another 43 athletes analyzed separately for validation, those with high-risk profiles were 5.14 times more likely to sustain a second ACL injury than the low-risk group.

“Standard clinical measures may be able to be used to identify patients at high risk for a second ACL injury,” said Mark V. Paterno, PT, PhD, MBA, SCS, ATC, acting scientific director of orthopedic and sports physical therapy at Cincinnati Children’s, who presented the findings in San Antonio.

In a second presentation, researchers from the University of Florida in Gainesville found that preseason weightbearing asymmetry during a drop-vertical jump was significantly associated with risk of a lower extremity injury during the subse­quent sports season in 137 collegiate football, volleyball, and basketball players. Asymmetry greater than 23.1% of body weight was associated with a positive likelihood ratio of 1.47 and a negative likelihood ratio of .88.

Weightbearing asymmetry during an overhead squat or a single-leg forward land, however, were not associated with injury risk, said Debi Jones, DPT, OCS, SCS, a member of the sports physical therapy faculty in the university’s Department of Orthopaedics and Rehabilitation, who presented the findings.

“These findings may tell us that asymmetries are present in all athletic tasks, but only those related to the drop jump task may be predictive of injury,” Jones said.

In a third presentation, researchers from George Fox University in Newberg, OR, found that preseason scores for standing long jump and single-leg hop for distance were associated with lower quadrant injury risk in 80 female collegiate volleyball players.

Those who jumped less than 70% of their height were 12.2 times more likely to have a lower quadrant injury than their counterparts; those who jumped less than 80% of their height and hopped less than 70% of their height were 5.7 times more likely to have a foot or ankle injury.

Preseason testing can help clinicians efficiently target athletes who may need additional preventive training to avoid injury, said Jason Brumitt, PT, PhD, ATC, an assistant professor of physical therapy at the university, who presented the findings in San Antonio.

“You often don’t have a lot of time to get athletes ready, especially for fall sports,” Brumitt said.


Paterno MV, Huang B, Thomas S, et al. Clinical factors predict second ACL injury after ACL reconstruction and return to sport: Development of a clinical decision rule. J Orthop Sports Phys Ther 2017;47(suppl 1):A47-A48.

Jones D, Tillman SM, Moser M, et al. Preseason weight-bearing symmetries differ in athletes sustaining lower extremity injury during the competitive season. J Orthop Sports Phys Ther 2017;47(suppl 1):A41.

Brumitt J, Mattocks A, Lentz P, et al. Lower-quadrant time-loss injury rates and preseason performance risk factors in female collegiate volleyball players. J Orthop Sports Phys Ther 2017;47(suppl 1):A33.

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