By Sara Rider
In Texas and across the country, the number of middle and high school girls playing sports is on the rise. According to the National Federation of State High School Associations (NFHS), the number of girls participating in sports has more than doubled in the last 20 years. That’s the good news. But with that growth in sports participation has come an increased risk of injury for girls, according to the American Academy of Pediatrics (AAP). That’s the bad news.
Now the AAP says that research indicates the risk for one particular type of injury—tears to the anterior cruciate ligament, or ACL—may be able to be reduced. The AAP report (“Anterior Cruciate Ligament Injuries: Diagnosis, Treatment, and Prevention,”Pediatrics, May 2014) says that specific types of physical training can reduce the risk of ACL injury, especially in young women.
Sports and strength
According to the NFHS, nationally some 55.5 percent of high school students play sports of some type. The leading choice for girls is track and field, with some 475,265 participants, followed by basketball at 438,933, and volleyball with 409,332. Soccer comes in fifth with 361,556 girls participating nationally. And Texas leads the way in number of participants overall, with 786,262 boys and girls involved in sports.
That’s a lot of young people running, jumping, stopping and starting. And all of those movements put their knees at greater risk of injury, says Orthopedist Dr. Randall Schulz, of Texas Orthopedics.
“We know that high velocity sports are the ones that really put them at risk (for knee injury), so soccer is a big one, basketball as well and probably to a lesser degree volleyball and softball.”
Anatomy and risk
According to AAP, the anterior cruciate ligament is one of the major ligaments that stabilizes the knee, helping to protect it when the person jumps or pivots or slows down suddenly while running. When pre-teens enter puberty they grow taller and heavier, and this puts the ACL at greater risk as well; for girls, this risk begins at age 12. And girls have a higher risk of ACL injury overall because as their body size increases, they usually do not develop more muscle power.
But if you have a daughter who plays soccer or basketball, or any sport that involves jumping or stopping and starting quickly, how do you know at what level of risk she is for tearing her ACL? And what can you do to reduce her risk? “First, I would look at family risk,”advises Dr. Schulz. “Have other members of the family had problems with ACL tears? Then I would look hard at the sports they’re playing and how common ACL injuries are in those sports.”
According to the AAP, special types of physical training can reduce the risk of ACL injury by as much as 72 percent in young women. The recommended tools: neuromuscular and strength training.
As good as the boys
According to Angela Rich, ATC, PT, Sc.D, of Elite Physical Therapy, several types of neuromuscular exercises can help girls avoid ACL tears. The goal of the exercises is to overcome some of the differences in girls’physique and strength that can put them at greater risk than boys for ACL tears. Some of the differences in body build and strength begin with four variations in the way girls land on their feet, compared to boys.
First, girls’ quadriceps (the muscle group in the top of the thigh) is the dominant, or strongest, muscle in the leg, explains Rich. This means that girls don’t use their hamstrings or their knees as much when they land or change direction during sports.
“Males have a tendency to use their hamstrings more and to absorb shock with their knees,”explains Rich.
Next, in girls one leg tends to be stronger than the other leg, while in boys, both legs usually have the same strength. “Research has found that females tend to have one stronger leg,”explains Rich. “So what happens is that when you’re landing, you’re basically landing off balance, and that sets you up for an ACL injury.”
The third factor that makes ACL injuries more common in girls is that girls “have less core strength and stability than boys,”says Rich. This makes it harder for girls to have control over their bodies during physical activity. The fourth factor that sets young girls up for injury is that they tend to not use muscle mass to stop forward movement—they rely instead on their bones and their ligaments.
Putting the brakes on
To overcome these problems, parents can turn to neuromuscular training for their budding athlete.
“Research has shown that neuromuscular training can reduce risk of injury in girls,”says Rich. “The key component of a neuromuscular program is progressive strengthening of the core and the legs. So we are talking about squats, lunges, single leg bridging, planking—that is all part of the strengthening.”
Neuromuscular training also includes plyometrics, or repetitive jumping. “You start with jump squats—so you stand in place, squat and then jump,”explains Rich. The training program progresses to single leg exercises and then jumping for distance.
But how do you know if your daughter needs neuromuscular training?
“I would want to take a look at their body mechanics and see how strong they are,”says Dr. Schulz. “If they’ve grown rapidly, do they have a hard time carrying their bodies around in a coordinated fashion?”
Dr. Schulz acknowledges that this can be hard for any parent to assess, but says there are training programs and therapists they can work with to first assess their daughter’s individual risk and then develop a program to reduce that risk.
“A lot of it comes down to the position of the foot relative to the knee, and then the ability to have the strength to control and slow down a rapid deceleration or a quick change in direction,”explains Dr. Schulz.
Rich recommends that parents pay attention to how their daughters land when they jump. “Do they land with their legs straight? Do they tip to one side? Is their trunk forward? If you think it doesn’t look right, then a professional should assess it.”
Obviously, no competitive middle school or high school athlete wants to be sidelined by injury. But an ACL injury can have more far-reaching consequences. “The real long-term problem with an ACL injury is that many times it damages the cartilage in the knee,”says Dr. Schulz, “and that can lead to early arthritis.”
According to Rich, research shows that regardless of whether you have ACL surgery following an ACL injury, “the likelihood of developing osteoarthritis was the same. So you can fix the ACL, but the problem of osteoarthritis is still there.”
But a future with osteoarthritis of the knee doesn’t have to be a given. “I think it’s exciting that for the first time we have some evidence that we can slow these injuries down,”says Dr. Schulz. By incorporating more neuromuscular training into a young athlete’s preparation, the risk of future problems can be reduced.
“Optimum training begins in early adolescence,”says Rich. “You have to develop strength, and develop muscle memory.”
And that combination can mean a reduced risk for an injury that can keep your daughter from enjoying and succeeding in a sport she loves.