Why Your Knees Hurt

Despite the common belief that running is bad for your knees, there's really nothing inherent in the activity that wreaks havoc on them. In fact, a recent study found that running can even protect knees. But if you've heard of, or suffered from the dreaded "runner's knee," you know that this type of pain is a common complaint in the sport. Turns out, it's not the running itself that causes the wear and tear. Other factors, including your habits and, surprisingly, even your sex, determine whether your knee is your Achilles heel.

There's a lot of evidence that women tend to be quad dominant,

said Dr. Ross Henshaw, orthopedic surgeon. Meaning that for reasons that aren't quite understood, women tend to use their quad muscles more than their hamstrings, putting excessive pressure on the kneecap, which can result in pain over time.

For example, when a man jumps off a chair and lands on the floor, his quads might contract 60 percent and his hamstrings 40 percent. When a woman does the same thing, her quads might contract 80 percent and hamstrings only 20 percent. 

For female runners who want to treat or prevent knee pain, Henshaw suggests doing exercises that strengthen the hamstrings, like hamstring curls or lunges.

Lunges are good because they promote co-contraction of the [hamstrings and quads] and they indirectly teach posture. Good posture helps protect the knee and prevents other injuries,

he said. Henshaw has also found that certain times of the year tend to yield more knee complaints. During the holidays, for example, many runners increase their mileage to compensate for eating more than usual.

The muscles and tendons can't adapt quickly to an abrupt change in intensity and duration of workouts,

Henshaw said. That old rule of increasing your mileage no more than 10 percent a week should stand firm, even in the face of too much pecan pie.

Another common culprit is your running terrain. Hill workouts can trigger pain in the knees because it puts more emphasis on hamstrings. It also forces the knees to remain flexed, which causes the IT band to

sort of windshield wipe over the thigh bone. That friction can cause pain.

Keep your hill workouts to a minimum and make stretching your IT band a regular part of your routine.

Henshaw also suggests treating pain much like you would treat an infection. Most people, he said, take an anti-inflammatory at the first sign of discomfort, then stop when the pain subsides only to have it return later. Henshaw advises his patients take anti-inflammatories on a schedule for a week. This allows for the inflammation to go down and keeps it from returning.

Even if you suffer from knee trouble, you don't necessarily have to give up running -- or be afraid to start. Consult a doctor and consider adjusting your distance and your terrain. And ladies, give your hammies some love.