If you're a sports fan, then you've probably heard of the high number of Anterior Cruciate Ligament (ACL) tears among pro athletes in the last year.
Among the most recent cases are Boston Celtics point guard Rajon Rondo and  Chicago Bulls star Derrick Rose. Timberwolves guard Ricky Rubio also fell victim and Washington Redskin Robert Griffin III, or RG3 as he's more popularly known, went down with a nasty tear in the late part of last year's season.
Timothy Hewett, PhD, who's the director of research at Ohio State University's sports medicine program is an expert on ACL injuries, and he says it's not only pro athletes who suffer these tears, young sports players, especially on the high school level, are getting these injuries too.
"At the high school level it's estimated between 120,000 and 350,000 ACLs occur in the U.S. every year or at least 50,000 a year. It's a big problem," said Dr. Hewett said in an interview with ConsumerAffairs.
"And girls at that level are significantly more susceptible than boys in the range of four- to six-fold, because they demonstrate these neuromuscular imbalances more often than boys do."
Screening test
An indication of an athlete having a neuromuscular imbalance is when they favor one leg over the the other, after landing from a rebound in basketball, after coming down from spiking the volleyball or playing any sport that involves frequent jumping.
And to determine if one does have an imbalance, Hewett and his team have come up with screening methods that can tell an athlete if he or she has an increased risk of developing an ACL injury.
Two of the tests that Hewett mentioned entail jumping off a box about a foot off the ground, while lining your feet up with the width of your shoulders.
If you consistently land on the ground with the width of your legs decreased by half of the amount when you jumped, you're in danger of getting an ACL tear, says Hewett.
Another test to determine if you're at risk is by putting an "X" on the floor using tape.
By jumping in all four sections of the "X," kind of like hopscotch, you'll be able to determine if you're favoring one leg over the other, and if you are, you could be on your way to damaging your ACL.
Higher risk
Hewett says these screenings, which can be done by both doctors and by athletes  themselves at home, will accurately tell if one has a muscular imbalance and if they're susceptible to injury.
"What we do know in our last 15 years of work is that certain people are at higher risk of tearing their ACL than others are," said Hewett. "And basically, what we've developed is a research paradigm and a parallel screening method where we look for specific neuromuscular imbalances that we know are predictive of injury risk and these four imbalances we call ligament dominance."
"Like in Newton's third law, he tells us if you hit the ground or if you hit anything that has an equal and opposite reactive force, [like when a basketball player lands on the court], the court hits them back with equal and opposite force, which is actually multiples of their body weight, because their body mass, their body segments have inertia, momentum," Hewitt said.
"So the floor is hitting them back with three, four, five, six times the body weight, depending on how they land, whether it's with a flat foot, a straight knee or flex knee," he said.
And Hewett says the screening can predict if a player is at risk of getting an ACL tear with about 80% specificity, and through training and conditioning, doctors can teach an athlete how to properly land, so they can decrease the chances of an injury  by about 62%.
Tested in Ohio
These screenings have been conducted in Hewett's local school system and at Ohio State University for over 10 years, where students are tested and retrained before the season begins and then retested after it concludes, so Hewett and his team can gauge how effective their training protocols were.
Hewett, who in addition does ACL research and training for the NBA, says the kind of sports that cause ACL injuries the most are soccer, volleyball, football and basketball and once you tear your ACL, you're about 25% more likely than the average person to tear it again.
And the first time you develop a tear some might opt for surgery right away, while others may opt for therapy, and according to Hewett, whether you'll continue to play that sport will most likely determine which option is best for you.
It really comes down to a rule of thirds, he explains.
"About a third of people can function okay without an Anterior Cruciate Ligament, even going back to sports," says Hewett.
"About a third can function without an Anterior Cruciate Ligament if they don't go back to sports and they just [do] everyday activities of living and about a third can't function at all, even in their activities of daily living, without an ACL -- so if you're going back to sports about two-thirds of people need to have their ACL reconstructed."
In addition, it will take an average of at least six months before a person with an ACL tear can return to sports and oftentimes athletes will take a whole year off, Hewett says.
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