In 2006, several months after injuring her knee playing ultimate frisbee, Emily Reynolds was knocked down by a rogue wave while swimming in the Outer Banks. In pain, she returned to the doctors who had previously diagnosed her with a sprained knee.
“I went back and had an MRI. I had torn my ACL and my meniscus. Had I done it in the first place? I think yes, but I’m not a medical doctor,” Emily said.
Today, six years later, she is still dealing with the complications of the injury to her anterior cruciate ligament, the ACL. And, she’s got plenty of company, at least four of her teammates from the William and Mary Women’s Ultimate Frisbee team have suffered tears or partial tears to the ACL. While that may sound like just really bad luck, statistics show that female athletes are about 5 times more likely to tear their ACL then male athletes, usually during cutting or jumping sports like soccer, basketball, and yes, ultimate frisbee.
While men usually sustain ACL injuries from contact injuries, like a football tackle that bends the knee the wrong way, women’s injuries happen without contact more than 70% of the time. One of Emily’s teammates, Laura Muskavitch, explained that her own knee injury, and others she’s seen, occurred during very routine activity.
“Sometimes, its just turning around in a drill. It’s amazing to me that such a dramatic injury, in terms of the surgery and recovery, can happen in such an undramatic way. Just turning around in a drill, you can be out for the season.”
Turning quickly requires knee stability, and the anterior cruciate ligament, one of 4 ligments in the knee joint, is primarily responsible for that stability. Doctors, physical therapists, coaches, and athletes have known for a long time that women seem to tear this stabilizing ligament far more frequently then men, but only recently has research begun to understand specific risk factors for these injuries. Data from this research has lead to injury-prevention training programs and injury-risk screening tests.
According to Dr. David Bell, an ACL injury researcher at University of Wisconsin Department of Kinesology, there are 4 categories of factors that play into an athlete’s risk for ACL injury. The first is hormonal, because women have estrogen and progesterone receptors on their ligaments, which function to cue the ligaments to become more flexible during childbirth. However, the presence of these receptors means that women’s ligaments become slightly more flexible when they are menstruating, which can slightly increase the risk for joints injury. Secondly, everyone’s knee anatomy is slightly different, and some people maybe be at higher risk because of the placement of the ACL or the groove that it lays in.
The third category of factors is bio-mechanical. Bell explains that, on average, female athletes perform activities that load pressure onto the ACL, like cutting and landing from a jump with more erect postures then men. They typically bend their knees less, and are more likely to let their knees collapse inward. All of these positions lead to increased stress on the ACL. Lastly, how your muscles react when you jump or cut can play a role. Bell said that the most common problem is that women tend to be quadriceps dominant, with less hamstring strength then men, which is also creates more strain on the ACL.
Strengthening exercises for the hamstrings and other stabilizer muscles play a big role in the physical therapy for people recovering from ACL reconstruction surgery. It’s a long, slow recovery.
“I’d say it was atleast half a year before I could run around at all, braced up.” Emily said. “It was a year before I felt fully recovered, and it was the end of 2009 before I really could run and get back in shape, but my recovery was complicated by Lyme disease.”
Once she got her lyme disease treated with intravenous antibiotics, Emily was able to return to running and sports. She dedicated herself to careful strength training, trying to keep the stabilizing muscles that support her knees healthy and strong. Despite her efforts, she re-injured the same knee in September of 2011, tearing her meniscus again when she was squatting down to move things around in a low cabinet.
“The way you tear it is when you knee is bent and you twist it,” Emily said. “I somehow found that special angle of foot rotation, knee placement, and hip location that my knee just couldn’t handle.”
Re-injuries like Emily’s are common, according to Dr. Bell. Once you’ve torn your ACL once, you are 10 to 15 times more likely to suffer another tear. However, unlike Emily, most people who return to high level sports and suffer another ACL injury tear their opposite knee. Bell speculates that people might need more rehabilitation before they return to play. His data suggests that after an injury, some people move with bad bio-mechanics, trying to protect the reconstructed knee, and increasing the stress on the other knee.
The stress on the healthy knee is something that Emily can relate to. “I have a remaining small sense of instability. It might be psychological, but both my knees feel fragile now. My other knee has been doing all the support for so long that it’s starting to wear down,” she said.
Repeated injuries do wear down the joint, increasing the risk for developing osteoarthritis and future injuries. It’s a viscous cycle, where bad mechanics of movement can lead to injuries, which lead to worse mechanics of movement, which can lead to more injuries. To break this cycle, Bell recommends injury prevention training programs for sports teams. These programs, which focus on healthy bio-mechanics, have been shown to reduce injury rates by 50%.
“It’s all about quality of motion, reminding people how to do it correctly,” Bell said. “Pylometrics, done very slowly, very controlled. You want to keep the landing forces under control.”
The video below shows a modified PEP program for women’s ultimate, by Dr. Jamie Nuwer. A full, 15 minute workout from the Santa Monica Sports Medicine Foundation can be found here.
Another former teammate from William and Mary, Jill Bingham, believes that the rate of ACL injuries are particularly high in Ultimate because, unlike soccer, there not as much coaching and not as much awareness of the importance of teaching the fundamentals of how to move.
“So, I’m coaching high school kids frisbee and I’m teaching them how to jump and how to land, and I think that if more people start to pay attention and do this, it will get better,” Jill said.
Unfortunately for many young women like Emily, it’s too late for injury prevention programs. Now after two surgeries on the same knee, she focuses on a second round of rehab and depends on her knee brace for any running or sports.
“It’s been a long road, I’ve seen four orthopedists and 1 sports medicine doctor,” Emily said. “I can ride my bike though, pain free, without a brace. That’s my saving grace.”
(Disclaimer, I played ultimate at William and Mary with Emily, Laura, Jill, and many other teammates who’ve sustained ACL injuries. That experience inspired me to pursue this research.Photo credits to another teammate, Austin Bridgforth)