The patella, or kneecap, is a small bone on the front of the knee joint. Patellar subluxation occurs when the tendons that stabilize the kneecap abnormally slip out of place. This condition, which is also referred to as a partial patellar dislocation, typically occurs following traumatic injury to the knee joint.

Knee pain is a common reason that people visit their doctors. The knee is the largest weight-bearing joint in the body and takes significant stress when an individual walks, runs, or plays sports. The knee has obvious actions, including flexion and extension or bending and straightening.

The knee is a complex joint made up of bone, cartilage, ligaments and other soft tissues. Because of its involvement in walking, and wear and tear sustained in intense athletic activities, the knee is prone to injury. Pain in the knee with occasional popping when walking may be a sign of soft tissue injury or fracture.

Knee joints sustain plenty of use every day that stinging pain is common. It may be the result of a previous sport injury or arthritis. Fortunately, knee pain can be stopped with adequate preparation.

Nothing can ruin a cycling trip faster than knee pain. When every push of the pedal causes discomfort, you'll either be in constant pain or opt to end your ride early. Pain that comes from the head of the fibula can be caused by a number of things, so it's important to talk to your doctor as soon as it happens.

Patellar alignment issues are common sources of knee pain. The patella, or kneecap, moves up and down as the knee bends and straightens. It moves on a "track" called the trochlear groove. When the kneecap doesn't move on the groove correctly, the condition is referred to as a patellar alignment (or tracking) problem.

Pinpointing the cause of pain in the back, or posterior, of your knee can be like solving a puzzle. Many different conditions can cause pain in this area, some much more common than others.

Just because you have bad knees doesn't mean you need to stop exercising. In fact, certain exercises, such as step exercises or exercises using a resistance tube, can be beneficial for people with bad knees, according to certified personal trainer Dan Falkenberg in an article for ColumbusSports.com.

Pain in the front of the knee is most often associated with the patella or kneecap, and is generally classified as patellofemoral pain. According to the American Academy of Orthopaedic Surgeons, contributing factors to patellofemoral pain include overuse, muscle imbalance and inadequate stretching.

Lunges are excellent dynamic strength exercises for the lower body but can cause pain if not performed properly. Past knee injuries, poor core strength and tight muscles may also contribute to knee pain during lunges.

The knee joint is prone to injury, especially if you participate in activities in which you frequently start and stop, jump, run, change directions or twist. Cartilage covers the ends of the bones in your knee, and the pieces of cartilage between the bones are called meniscus.

Pain is common immediately after anterior cruciate ligament, or ACL, reconstruction surgery. With time and active rehabilitation, this pain should decrease and eventually disappear. There are several causes of pain that starts days to years after surgery.