Is knee pain holding you back? Here to discuss the various injuries that can hurt this complex joint is the PGA tour doctor, Vijay Vad. A knee injury can be extremely uncomfortable and may even prevent you from participating in your favorite activities. Let's look at some of the more common causes of acute knee pain. The knee contains four ligaments, large bands of tissue that connect the bones together. The two that are on the inside of your knee, the posterior cruciate ligament, or PCL, and the anterior cruciate ligament, ACL, are the most likely ligaments to tear and cause injury. A torn ACL usually results from sports that involve slowing down or pivoting rapidly, like skiing or basketball. People who play these sports may feel or hear the 'pop' characteristic of a torn ACL injury. After suffering this injury, it is unlikely that you'll be able to immediately put weight on the injured leg. A meniscus injury can also cause knee pain. The meniscus is a C-shaped piece of cartilage which helps the bones glide past each other. Meniscal tears can occur in a golfer when a flexed knee puts excessive torque on the meniscus, causing a tear. Several years ago, golf fans were shocked when Tiger Woods retooled his legendary swing. One reason why Tiger opted to make this change was because his powerful swing was damaging the meniscus in his left knee. Tendons are fibrous bands of tissue which connect muscles to bones. Tendinitis results when one of the knee's two tendons becomes inflamed. The discomfort of tendinitis usually isn't constant, but occurs during periods of activity. Tendon injuries often occur in people who ski. These injuries can also result from inflammatory diseases, like rheumatoid arthritis. Iliotibial band syndrome is a form of knee injury that occurs when the ligament that extends from the outside of the pelvic bone to the inside of the tibia leg bone becomes so tight that it rubs against the upper thigh bone, the femur. The sharp, burning pain that results from iliotibial band syndrome is commonly found in distance runners. Often, the pain doesn't begin until 10 or 15 minutes into a run. Another painful injury, a dislocated kneecap, occurs when the bone that covers the knee slips out of place, often to the outside of the knee. This injury is usually visible to the eye and is bound to cause pain and swelling in the affected area. Bursitis of the knee is another known cause of knee pain. It occurs when the bursae, small sacs of fluid which cushions the knee joints, become inflamed and painful. Sometimes called "housemaid's knee," this injury often occurs after long periods of kneeling. A variety of injuries can cause the serious burning, swelling and discomfort that is characteristic of knee pain. If left untreated, knee injuries may recur or become worse, so please see your doctor at the first sign of pain.