When Gretchen Zelek took up running at age 40, she developed a convert’s enthusiasm, logging three miles a day, five days a week. But a few weeks into the new regimen, her knee started hurting. “The pain, which was under the kneecap, would start shortly after I began each run and progress until I had to stop,” recalls the 54-year-old Pasadena, California, resident.
Frustrated, she sidelined herself and started taking Pilates classes several days a week. After Zelek described her knee problem, the teacher suggested moves to stretch and strengthen the hips. Five months later, her hips strong and limber, Zelek laced up her running shoes again and found she could move without pain; a year and a half after that, she ran her first marathon without so much as a twinge. That was 13 years ago, and the knee problem has yet to recur. “I run regularly, but I’m pain free—and pretty fast,” Zelek says.
Why should the strength of your hips affect your knees? It’s all about stability. Experts have long known that having a strong core (aka the trunk of your body) is essential to avoiding pain and injury, but until recently, core meant abs and back; the hip muscles weren’t included. That’s changed, thanks to a slew of recent studies confirming that the hips play a key role in balancing, aligning and supporting body parts from the low back on down. “Weak hip muscles are an often-overlooked cause not only of common sports-related injuries, such as runner’s knee, but also of low-back pain in nonathletes,” says Reed Ferber, PhD, director of the University of Calgary’s Running Injury Clinic and a leading researcher on hip strength.
This news is important for women, because we are prone to weak hips, especially as we age. When researchers from Texas Woman’s University and the Cooper Institute, both in Dallas, compared the functioning of women ages 20 to 83, they found the biggest difference appeared in the strength of the hip abductors, the group of muscles that help rotate legs outward. In the study, women 55 and older were 24 percent weaker in these stabilizing muscles than the 20- to 39-year-olds. And that weakness, says a growing body of research, contributes to a large array of lower-body troubles, such as sore knees, lower-back pain, twisted ankles and inflamed iliotibial (IT) bands (connective tissue that runs along the outside of each leg from hip to knee).
The thighbone’s connected to the . . .
To understand how weak hip muscles can affect other parts of the body, consider how they relate to the functioning of your knees. If the major muscles at the outside of the hip are not strong enough to keep your leg stable, the thighbone may move inward when you walk or run, causing that bone to rub against the back of the kneecap, says Tracy Dierks, PhD, director of the Motion Analysis Research Laboratory at Indiana University–Purdue University Indianapolis. “This friction basically wears away the cartilage,” he says. No wonder, then, that of 284 patients seen for knee complaints at Ferber’s running clinic over seven months, 92 percent had weak hip muscles.
Out-of-shape hip muscles have also been linked to low backaches. “When the hips become weak and inflexible, they can place extra demands on the muscles of the back, throwing it out of alignment,” says Ferber. In addition, weak hips can put ankles and feet at risk. If the hips don’t bear as much weight as they should, Ferber explains, “that puts too much pressure on the small muscles surrounding the ankle and foot—and when they get fatigued, you’re more likely to get injured.”
A simple solution for aches