Health and fitness for life.

How accurately can you describe your feet? Most dancers can relate every line and curve; feet demand, and get, plenty of attention. And most dancers know which hip is more flexible, which has better turnout. But most dancers are not familiar enough with their knees. Although the lower extremity in general is reported as the site of most frequent injury for dancers (with the foot area ranked first), the vulnerable knee is a close second.

According to Carol Teitz, MD, one of the biggest concerns with dancers, especially in forms that accentuate the use of turnout, is kneecap, or patellofemoral, problems. The kneecap rides in a specific groove of the thighbone, and if the muscles are unbalanced, pain can begin from the kneecap grinding on the groove the wrong way. In a worst-case scenario this tightness can pull the entire kneecap off of the groove. If the muscle imbalance is due to lack of bony hip rotation, the big, tendinous side strap of the thigh, the ilio-tibial band, tries to do the work of the hip joint in rotating the leg, which then pulls the kneecap sideways.

Also, the knee rotates with every step (called the screw-home mechanism); the thigh (femur) goes in one direction and the shin (tibia) goes in the other. In turnout, if the side of the leg is too tight or the hip joint won't allow rotation, many dancers will over-rotate the knee, which can create enormous pressure even during a simple plie. In dances that require many squats or in modern dance forms that use the floor or knee turns a lot, one of the cartilage discs (meniscus) may tear. The two menisci function as padding between the femur and the tibia, moving with the bones to allow more motion in the legs and feet. When the menisci get torn, they can roll up and get caught inside the knee, causing it to lock up or just be painful and inflamed. Fortunately, the leg can function without the menisci, so they can be partially or fully removed; but lack of a meniscus can cause arthritis later.

Overuse is a problem that can lead to patellar tendinitis, or jumper's knee, where the tendon between the kneecap and the tibia gets inflamed. Although this painful condition may take a while to resolve with rest and ice, improved dynamics can help considerably.

Probably one of the most debilitating (though not common) injuries involves the ligaments, usually the anterior cruciate ligament (ACL), which forms a cross deep inside the knee with its sibling, the posterior ligament, and keeps the femur from sliding off of the tibia. It tends to happen in ballet when landing large jumps, or in forms such as contact improvisation, in which the body twists while the foot stays in contact with the floor.

Form is everything in injury avoidance. Keep your kneecap in line with the second toe. Develop the deep postural muscles of the pelvis and leg, such as the inner thighs and hip rotators, giving equal attention to both the internal and external hip rotators. Lift the kneecap to straighten the leg instead of pushing the knee backward into hyperextension. Stretch the large muscles of the thigh, the quadriceps. Roll the side of the thigh on a foam roller to keep the sides of the legs from becoming overly tight. Improve your balance and pelvic-side muscle coordination by standing on one leg in parallel for twenty seconds with arms crossed and eyes closed. And never forget that hamstring strength is as important as stretch.

What we think translates into our bodies. When an actress portrays a character, viewers see her emotions physically, on her face and in her body. Use your mind as well as your muscles to improve your body's mechanics, and your knees, caught in the middle of all that action, will last a whole lot longer.

Suzanne Martin maintains a private practice in physical therapy and Pilates.