Under the knee cap and covering the ends of the femur (thigh bone) and tibia (shin bone) is a sort of natural shock absorber made of cartilage. This shock absorber does not come with a lifetime guarantee; wear and tear over the years can result in a loss of mass of the shock absorbing cartilage. Once some of this cartilage has degenerated, the knee obviously cannot absorb or handle shock from running, for example, as well as it could before. This condition is referred to as "chondromalacia patella."

Technically, chondromalacia is an overuse injury that causes a dull, aching pain under and around the knee cap. Climbing stairs, walking up hills, and doing anything that involves a fair amount of running can all become painful activities for someone with chondromalacia patella. This knee condition is fairly common among runners — by some estimates, almost 30 percent of runners develop this condition. Skiers, cyclists, and soccer players also have a higher risk for chondromalacia patella. The tendency to develop chondromalacia patella also seems to run in families.

Everyday that you get up is a day of stress as far as your knees are concerned. Walking around, climbing stairs, running, dancing, waiting in lines — all of these activities put some amount of stress on the knees. As far as joints go, the knee is the largest one in the body; it's also multi-talented, acting as a hinge, a lever, and/or shock absorber at any given time. For support, the knees rely almost entirely on soft tissue (ligaments, tendons, and muscles), which isn't always the most reliable. It's no wonder that knee pain and injury are so common!

You can do some things to prevent (further) knee injury and pain. Always wear good, supportive shoes that aren't worn out, especially when you exercise. Have a health care provider check your feet to make sure that they aren't contributing to a misalignment of your body that puts undue stress on one knee over the other. Or, if you get a chance to see a physical therapist, ask her/him to check the way you walk. If you ride a bike regularly, make sure that your seat is up high enough so that your knee is only slightly bent at the bottom of a pedal stroke. If you're a runner, avoid running on uneven surfaces as much as possible to lower your risk of falling and/or twisting your knee.

If, after every time you engage in a certain sport, say racquetball or running, you experience a great deal of knee pain, you might want to take a break from that particular activity and try a few that won't aggravate your knees (hopefully). A few "easy on the knees" sports are swimming, slow jogging, walking, and cross-country skiing. If you choose swimming, be aware that strokes involving the frog kick will put more stress on your knees than those that use a straight-leg, flutter kick. Any sport that requires deep knee bends and/or twisting at the knee causes knee pain most often.

It's extremely important to strengthen your leg muscles, especially those that support your knee, primarily the quadriceps; but, it's best to work on the leg as a whole so as not to favor one muscle group over another (this, too, can lead to injury). Remember, the knee doesn't have much of a support system, so you need to do all you can to build up what it does have. Ask your doctor to show you some strength building exercises you can do or, perhaps, to refer you to physical therapy long enough to build up strength and reduce any pain you are experiencing. You might also want to see an orthopedist.

Alice