ACL Knee Injuries and Prevention Strategies with Dr Timothy Hewett

Dr Timothy HewettPhysical Therapy Continuing Education.Org recently had the pleasure of interviewing Dr Timothy Hewett, PhD about his work with Anterior Cruciate Ligament injuries and prevention strategies.

Dr. Hewett is the Director of Sports Medicine Biodynamics Center at Children’s Hospital Research Foundation. He’s also a Professor in Pediatrics and Orthopedic Surgery in the College of Medicine, and an Adjunct Professor in Rehabilitation Sciences at the University of Cincinnati and Cincinnati’s Children’s Hospital Medical Center.

Listen to excerpts from the interview.


Dr. Hewett: So, we have many studies that go on in our laboratory that range from looking at young kids with Juvenile Rheumatoid Arthritis who go back to sports, and look at their joint loading patterns, to looking at young women and trying to figure out why they have a two to ten fold higher chance of injuring their ACL or developing patellofemoral pain, or developing advanced osteoarthritis earlier in their lives than males do.

Physical Therapy Continuing Education.Org: If we talk a little bit more general about ACLs, you just alluded to it, it seems like there’s a higher incidence in females than male adolescents.

Dr. Hewett: So, there was always this underlying risk, depending on the literature you read, anywhere between a two and ten times higher risk of an ACL injury in a young woman versus a young man.

In 1973, when Title IX was enacted, you had still that five-fold higher risk, but you had ten-fold or more, fewer players. So, there was less than half as many young girls and women suffering ACLs than we saw in males.

Then when Title IX was enacted it brought all these opportunities for women in collegiate sports. Basically in 1973 you had under 270,000 girls playing high school sports. Now you have about 3.2 million. Well over ten times more. So, now we see our clinics full of young girls with ACL tears.

Physical Therapy Continuing Education.Org: Is their mode of injury different? If you look at say contact versus non-contact?

Dr. Hewett: About 80 percent of all ACL injuries are non-contact injuries, whether it’s in a male or a female. For instance, obviously in the NFL, the National Football League, and men in collegiate football, you’re going to have more contact injuries than in women’s soccer or basketball. However, even in the National Football League, about 80 percent of ACL injuries are non-contact.

So, if you look at those four components of the mechanism that I talked about what I call these are ligament dominance, leg dominance, quadriceps dominance, and trunk dominance. These are what I call four neuromuscular imbalances that lead into these injury mechanisms.

Dr. Hewett: So, there are differences between males and females in mechanism, and I think when we design interventions we need to think about the difference in those mechanisms, and we need to think about different type programs for males and females.

For instance, in females you’re going to do a lot more core or dynamic trunk training than you’re going to gear toward males. Males, what we found, and what the literature shows, is that single balance in men is more important than women when designing an ACL prevention program.

It is a great interview with tons of useful information for any Physical Therapist who deals with ACL injuries.

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For more information on Dr Hewett, including his ACL workshops, click here.