Weak in the Knees?
Hormones and anatomy make women more prone to knee injuries.
Anatomy, Hormones, and Technique continued...
"It's like pulling an extra person off your back," he says.
Female athletes also tend to develop strong quadriceps muscles and
relatively weak hamstrings -- a dangerous imbalance of power, Hewett says. The
quads tighten the ACL, while the hamstring muscles relax it. Men generally flex
their hamstrings whenever they strain a knee, protecting the ACL. Women, on the
other hand, have a tendency to contract their quads.
Nobody knows the cause of these bad habits. "It could be genetic, or it may
have something to do with training," Hewett says. Whatever the source of the
trouble, it starts early. Hewett has noted straight-legged landings and weak
hamstrings in girls as young as eight years old.
Prevention Through Training
With these dangers in mind, Hewett and colleagues developed a six-week
training program that incorporates stretching, weight lifting, and seemingly
endless jumps with flexed knees. "It's all about mimicking situations that can
cause injuries, but staying in control," he says.
In addition to teaching proper jumping technique, the program works to
strengthen hamstrings and improve overall balance and agility, says Hewett. Any
activity that increases balance and control can help ward off knee injuries, he
The results have been impressive: As reported in the November/December 1999
issue of the American Journal of Sports Medicine, 366 female high school
athletes who completed the program were about four times less likely than
comparable athletes to suffer a knee injury during a season of play.
Back in Action
As for Walz, spending her off-season sweating through Hewett's program has
paid off. She's back to her starring role on the basketball court, playing more
minutes and scoring more points -- these days, with flexed knees and strong
All those practice jumps were exhausting, but she added a few inches to her
leap and gained some peace of mind. "I play all-out," she says. "I can't stop
to worry about my knee."