1. ACL injuries
The problem: Damage to the knee's ACL, or anterior cruciate ligament, has been shown to disproportionately affect females, says Rebecca Demorest, who treats pediatric and young adult athletes at the Hospital for Special Surgery in New York. The noncontact injury rate among female athletes is as much as 10 times that of men, according to the American College of Sports Medicine. And blowing out the ACL can sideline an athlete for a season—or, in the worst case, ruin a career.
Riskiest sports: Anything that requires planting the foot and changes in direction, i.e. basketball, field hockey, soccer, tennis, lacrosse, and skiing.
How to prevent it: One program, described in more detail here, appears to reduce the risk of ACL tears among female soccer players, according to a study that appeared last month in the American Journal of Sports Medicine. It focuses on training a woman's muscle memory to land and move differently, says Julie Gilchrist, lead author of the study and an epidemiologist in the Division of Unintentional Injury Prevention at the Centers for Disease Control.
The problem: One study suggests that in collegiate sports with similar equipment and rules, like basketball and soccer, women have higher game concussion rates than males. In hockey, the study found, the rates of concussion were similar, even though there are rules against body-checking in the women's game. The question is whether there are genetic differences that put women at true increased risk, or whether women are more honest about their symptoms and report their concussions more than men, says Demorest. Others have suggested that women's weaker neck muscles may play a role. Concussions, especially multiple ones, can have long-term implications.
Riskiest sports: Anything that puts you at risk of hitting the ground—or a hard object—with your head. Most of the research has focused on hockey, soccer, and basketball.
How to prevent it: Greater awareness of symptoms (such as confusion, amnesia, and dizziness) and necessary recovery time is important; athletes shouldn't return to their sport until symptoms vanish, which can take weeks. In addition, some have suggested more protective equipment—special headgear in soccer, for example. But it's not clear whether that would help.
3. Stress fractures
The problem: There's no clear evidence that stress fractures, which occur when a bone is stressed over time, occur more often in female athletes than males, Demorest says. That said, a stress fracture sometimes indicates deeper problems, like the female athlete triad—the combination of disordered eating, osteoporosis, and a lack of a menstrual period. All of those can have serious long-term consequences for bone and general health.
Riskiest sports: There are multiple risk factors, but girls in any sport involving repetitive motion—such as running, basketball, and tennis—are more vulnerable. Sports that value light weight, endurance, and aesthetics like cross-country running and gymnastics may be more likely to produce athletes who restrict their eating, which can contribute to stress fractures.
How to prevent it: The American Academy of Orthopedic Surgeons says that cross-training is a great way to avoid the repetitive motion that can lead to stress fractures. For example, instead of running seven days a week, athletes could run five days and swim or cycle the other two. Don't ramp up mileage or activity too quickly. Make sure your shoes are appropriate. And ensure you're eating a healthy diet that includes calcium and vitamin D, the AAOS advises.
4. Patellofemoral syndrome
The problem: This generalized ache under the kneecap, or patella, is caused by the irregular tracking of the patella and its painful contact with the femur. It's a problem for young athletes and also often strikes women. Their wider hips may put them at risk for the knee alignment problems that can make the patella track incorrectly.
Riskiest sports: While it is sometimes known as runner's knee, the injury can occur in any sport or activity that stresses the knees. Overuse is a major factor.
How to prevent it: According to the AAOS, key prevention strategies include keeping your weight down, since extra pounds stress the joint; gradually ramping up your training; and making sure you're using proper shoes and running with correct form. A coach or trainer might also be able to recommend strength exercises to correct any muscle imbalances that make the knee susceptible.