Sports-Related Knee Injuries

Skiers, football players, aerobic dancers, step-class participants and athletes who play basketball, tennis and racquetball all have one thing in common -- a propensity for knee injuries.

Such injuries account for 25 percent of all sports-related injuries, but proper conditioning can help prevent them.

Your knee joint is a joint where the femur (thigh bone) meets the tibia (shinbone). Muscles and ligaments hold the bones together. The surfaces of the ends of the femur and tibia are separated by a crescent-shaped layer of cartilage called the meniscus that prevents them from rubbing on each other.

Ligaments attached to several places on the ends of the femur and tibia to prevent the bones from sliding off each other. Two ligaments, the medial collateral and lateral collateral, anchor the tip of the femur to the tip of the tibia on the inside and outside edges of the knee. These ligaments stabilize the sides of the knee. Another set of ligaments are inside the joint, between the bones; they connect surface of the tibia to the surface of the femur. They are called the anterior and posterior cruciate ligaments. They prevent either bone from sliding too far forward or backward.

One important step you can take to protect your knees is to train properly by following the 10 percent rule: Don't increase the length or intensity of a workout by more than 10 percent in a week, according to the American Running Association (ARA). In addition, whatever your primary sport, it's important to do auxiliary leg-strengthening exercises that work the calves and quadriceps to help protect your knees.

Knees are vulnerable

Knee injuries usually are caused by overuse or impact, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS). Overuse injuries occur when the intensity and length of regular workouts are increased. They are also associated with anatomical variations in the knees, feet or legs. Inflammatory diseases such as rheumatoid arthritis also can damage the knee.

Impact injuries are caused by direct blows sustained in contact sports such as basketball or football.

Knee injuries can also result from falls, jumps or sudden knee twists when you're running, dancing or doing a step workout.

Tendon injuries

Tendons connect muscles to bones. Tendonitis, or an inflammation of a tendon, is a common overuse injury. Runners often develop pain at the back and outside of their knees, and athletes who jump a lot usually feel pain below the kneecap. Tendon pain is worse when you first get out of bed and eases during the day.

The key to treating the injury is rest, or at least a reduced workout. Heating the injured area before exercising and icing it afterward also helps reduce inflammation. Aspirin and ibuprofen can be helpful but shouldn't be used to mask pain.

Cartilage injuries

Cartilage injuries can be caused by overuse, impact, twisting movements or falls, according to the American Academy of Orthopaedic Surgeons (AAOS). These painful injuries make clicking noises and can make knees lock.

Small tears in the meniscus, the C-shaped discs of cartilage that rest on top of the tibia, may heal with rest over several months. Large or complete tears need medical attention. Surgery may be necessary, although rest or changing your activities may help.

Ligament injuries

Ligaments join bones to other bones. Impact and falls often cause ligament damage. Ligament tears are called sprains and often can be self-treated with RICE (Rest, Ice, Compression, Elevation) if they are minor. Large tears may require surgery and extensive physical therapy. Pain, swelling and a sense that your knee is "giving way" may mean there is serious damage to a ligament.

Runner's knee

Running can cause pain at or near the kneecap. An overuse injury will come on slowly or just after a longer or harder workout. It will go away when you stop running and return when you start again. If a biomechanical problem in your feet is causing the pain, treat the symptoms with RICE and see a podiatrist for orthotic inserts.

Treating knee injuries

Minor knee soreness caused by overuse usually can be self-treated with RICE, aspirin or ibuprofen. A week or two of treatment should yield significant improvement.

Knee sprains or mild traumas also can be treated with RICE. But see a doctor if there is no improvement in two or three days.

Seek medical attention immediately if you sustain a heavy blow, if you fall and hear a popping noise, if your knee is unstable and won't bear your weight, or if it clicks or locks.