Will New Programs Stem the Epidemic of Knee Injuries?

Laird Harrison


July 08, 2014

In This Article

An Epidemic of ACL Injuries

In the mid-1990s, Bert R. Mandelbaum, MD, realized that his practice at the Santa Monica Orthopaedic and Sports Medicine Group in Santa Monica, California, was changing.

"I saw a flip," he says. "My practice had been about 80% male and 20% female. And then it went to 80% female and 20% male."

Over in Ohio, renowned knee surgeon and orthopedic sports medicine specialist Frank Noyes, MD, was noticing something similar at the University of Cincinnati and among Olympic soccer players. The number of anterior cruciate ligament (ACL) injuries had more than tripled among National Collegiate Athletic Association (NCAA) soccer players from 1990 to 2000.[1] Researchers crunched the numbers and confirmed what the surgeons had noticed: Women suffer ACL injuries at 4-10 times the rate of men.[1]

Noyes, Mandelbaum, and others like them investigated this phenomenon. They found the cause, devised preventive exercise programs to address the situation, proved that the programs work, and shared them with the world. But their work has hardly staunched the tide of athletic knee injuries, leaving them groping for a next act. "We feel that it's a very unmet need," Noyes says.

Noyes estimates the incidence of ACL injuries in the United States at 300,000 per year. And the injuries can be devastating. One study found that only 44% of athletes are able to return to competition after ACL surgery.[2]

While men still suffer the majority of ACL injuries, the incidence of such injuries has risen as more people -- particularly more women -- participate in sports.[3] From the 1981-1982 school year to the 2012-2013 school year, the NCAA added 3071 women's sports teams and 749 men's sports teams to its roster, with the highest growth in women's soccer.[3]

Diagnosing the Problem

Noyes has some theories about why women, especially teenage girls, are blowing out their ACLs. "I observed that the way they moved in jumping and landing and cutting, the so-called 'wiggle-wobble knee,' made it apparent that there were balance and control issues that made them vulnerable to knee injuries," he says.

But not every female athlete is suffering this way. "I noticed that Olympic volleyball players had really good knee control," Noyes says. The reason, he theorizes, is the plyometric training that volleyball players do. "They jumped off mattresses," he observes.

To confirm the theory, his team videotaped men and women, injured athletes and noninjured athletes, as they jumped onto force plates that measured the impact of their landing. The investigators found significant differences. Among the most striking: Women -- and people who had suffered knee injuries -- were more likely to land harder, with their knees less flexed and more valgus.

In 1994, Noyes and colleagues at the Cincinnati SportsMedicine Research and Education Foundation, of which Noyes is President, began to develop Sportsmetrics™, a program of exercises aimed at reducing the risk for injuries. They were able to show that the training can change biomechanical metrics, such as the distance between the athlete's knees when landing from a jump.

A few years later, at a meeting of the American Orthopaedic Society for Sports Medicine, Mandelbaum and others who had noticed the trend toward knee injury watched hours of video showing athletes getting injured. They too noticed the awkward landings of the athletes who hurt their knees.

"I was the national team physician for US men's soccer and I felt it was my duty to put together a program," Mandelbaum says. Soon the Santa Monica Sports Medicine Foundation, of which he is Director, was testing the Prevent Injury Enhance Performance (PEP) program, which consists of a warm-up, stretching, strengthening, plyometrics, and sport-specific agilities to address potential deficits in the strength and coordination of the stabilizing muscles around the knee joint.


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