A week from today, 10,375 women - and 14,737 men - are expected to run in the Boston Marathon. The presence of so many women - the most ever entered in the historic race - is a sure sign of how far women have come in athletics.
So is this: In 1972, before Title IX, the law that spurred women's athletics, fewer than 300,000 high school girls played sports, according to the National Federation of State High School Associations. Now it's more than 3 million.
But there's a dark side to this terrific news: The more girls and women play sports, the more they, like boys and men, get hurt. And - attention athletes, coaches, and parents - they get hurt in different ways.
Last week for instance, researchers from the Center for Injury Research and Policy at Nationwide Children's Hospital in Columbus, Ohio, reported on a stunning injury rate for young gymnasts, 82 percent of whom are female.
Using data from 100 hospitals across the country, the team reported in the journal Pediatrics that every year, roughly 26,600 children ages 6 to 17 get injured badly enough doing gymnastics to wind up in the emergency room. This is a "very high" injury rate, roughly equivalent to ice hockey, said public health specialist Lara McKenzie, the lead author.
And gymnastics is just the tip of the iceberg. Cheerleading is now the leading cause of direct fatal and nonfatal injuries among high school and college women, according to the Center for Catastrophic Sport Injury Research at the University of North Carolina. "Cheerleading used to be about shaking pompoms," said the center's director, Frederick O. Mueller. "Now, it's about throwing people 20 feet in the air."
Basketball is not exactly benign, either: It's brutal on that most vulnerable part of the female athlete's anatomy: the knees.
And even plain old running seems to be tougher on women's legs than on men's, though it's not clear why.
This "absolutely does not mean that women should not play sports," said Dr. Lyle Micheli , a consultant to the International Olympic Committee on Women's Sports Issues and director of sports medicine at Children's Hospital Boston. After all, in two of the most popular high school sports, soccer and basketball, no significant differences existed in injury rates between boys and girls, according to figures released by the federal Centers for Disease Control and Prevention for the 2005-2006 school year.
But athletic activities can cause different injuries in women and girls than in men and boys. Female athletes and their coaches should pay increased attention to the anatomical differences that put girls and women at disproportionate risks for certain injuries.
The sports injuries that seem to disproportionately affect women include:
Women's knees are more vulnerable than men's because the "Q-angle" - the angle between the hip and the knee - is greater in women than in men. While wide hips are good for childbearing, they mean there is more stress on the knee in moves like landing from a jump and twisting. This torque can shred the ACL, a ligament that helps stabilize the knee. This is a major reason why female athletes have four times more ACL tears than men do, said Dr. George Theodore, a Red Sox team physician and sports medicine specialist at Massachusetts General Hospital.
Making matters worse for women's knees, especially among basketball players, is that women tend to "cut," or suddenly change direction, differently from men, said Micheli.
"There's more of a tendency for women to change direction on just one foot, maybe because of the width of the pelvis, while men often use two feet."
Wider hips also mean that there may be more "pull" on the kneecap, which can cause pain when running uphill. Kneecap cartilage also seems to wear down more in women than in men. And women's kneecaps slide around more from side to side, in part because women have more estrogen, which can make women's ligaments more flexible than men's.
Fortunately, solutions exist for these problems. One is better coaching for females - to teach them how to run, jump, land, and twist safely. Another is orthotics, devices that can be put in shoes to minimize stress on knee, ankle, and hip joints. And, of course, everyone should use appropriate safety equipment, such as thicker mats for gymnasts, helmets for cyclists, and headgear in soccer, which obviously benefit men as well as women.
Strength training, or weight lifting, is an absolute must for female athletes, just as for males, though the emphasis may be on different muscle groups. To help prevent knee injuries, for instance, female athletes need to work extra hard to build up a muscle on the inside of the knee called the vastus medialis and to build up hamstring muscles on the back of the thigh.
"We can't really change people's anatomy, but we can rebalance muscles with proper stretching, strength training, and orthotics," said Theodore of Mass. General.
It's clear that physical differences are not a reason to keep women from sports or from playing just as hard as men, said Laura Pappano, coauthor with Eileen McDonagh of "Playing with the Boys: Why Separate is Not Equal in Sports." Pappano said her daughter, now 13, was told that girls play nine-hole golf while boys play a full 18.
"The idea that women are doomed because of injuries is just absurd," Pappano said. "The whole 'girls will get hurt' argument has done more to limit women than anything else."
I couldn't agree more. Regardless of your gender, get out there and play hard. But train hard, too. And be sure to get the excellent coaching you need to keep you safe.