This fact sheet contains general information about knee problems. It includes descriptions and a diagram of the different parts of the knee, including bones, cartilage, muscles, ligaments, and tendons. Individual sections of the fact sheet describe the symptoms, diagnosis, and treatment of specific types of knee injuries and conditions. Information is also provided on the prevention of knee problems.

What Causes Knee Problems?

Some knee problems result from wear of parts of the knee, such as in osteoarthritis. Other problems result from injury, such as a blow to the knee or sudden movements that strain the knee beyond its normal range of movement. How can people prevent knee problems? Some knee problems, such as those resulting from an accident, cannot be foreseen or prevented. However, a person can prevent many knee problems by following these suggestions:

• First warm up by walking or riding a stationary bicycle, then do stretches before exercising or participating in sports. Stretching the muscles in the front of the thigh (quadriceps) and back of the thigh (hamstrings) reduces tension on the tendons and relieves pressure on the knee during activity.
• Strengthen the leg muscles by doing specific exercises (for example, by walking up stairs or hills, or by riding a stationary bicycle). A supervised workout with weights is another pathway to strengthening leg muscles that benefit the knee.
• Avoid sudden changes in the intensity of exercise. Increase the force or duration of activity gradually.
• Wear shoes that both fit properly and are in good condition to help maintain balance and leg alignment when walking or running. Knee problems may be caused by flat feet or overpronated feet (feet that roll inward). People can often reduce some these problems by wearing special shoe inserts (orthotics). Maintain appropriate weight to reduce stress on the knee. Obesity increases the risk of degenerative (wearing) conditions such as osteoarthritis of the knee.