Your knees are put under a lot of stress, whether you’re running, playing basketball, dancing, or simply cleaning your house. Just using the stairs can put pressure on each knee equal to four times your body weight.
Functioning simultaneously as a hinge, lever, and shock absorber, the knee is the key to your ability to stand up, walk, climb, and kick. Yet it depends almost entirely on soft tissue—ligaments, tendons, and muscles—for stability. Because of its complexity and the great forces to which it is routinely subjected, the knee is susceptible to a host of injuries.
Of all chronic knee injuries caused by overuse, runner’s knee—more accurately called patellofemoral pain syndrome, or PFPS—is the most common.
Prevention is the key
PFPS typically occurs when a misaligned kneecap (patella) irritates the connective tissue supporting the knee. Characterized by dull pain in or around the kneecap, it is most noticeable when you go down stairs, run, or squat.
Nearly 30 percentof runners eventually develop this disorder. Skiers, cyclists, soccer players and people who participate in any high-impact activities are also prone to it.
Research has shed light on a variety of underlying factors that can contribute to PFPS. These include biomechanical problems such as a kneecap sitting too high or tilted in the groove in which it rests on the thighbone (femur); knees that turn in too much; feet that are very flat or very highly arched; and various muscle-related issues that affect how the kneecap moves. Genetics may predispose you to some of these factors.
Women are at greater risk for PFPS than men for anatomical reasons. For instance, they have a wider pelvis, which increases the angle of the quadriceps (the large four-part muscle group on the front of the thigh) to the knee. They also have smaller knees with less restraining tissue and weaker supporting muscle.
The best way to prevent runner’s knee is to strengthen and stretch the muscles that power knee movement, especially the quadriceps and hamstrings, which are located in the back of the thigh. (The exercises below will get you started.) A weakness or imbalance in the quads, hamstrings, and/or hip muscles can contribute to improper tracking of the kneecap.