The fat pad in your knee sits just below your knee cap and provides cushioning and shock absorption between the bones of your knee joint. It is also known as Hoffa’s pad and is one of the most sensitive components of your knee joint.

The knees are highly prone to injury because they are the primary weight bearing joints in the body. Kneeling down exacerbates the pain of most knee injuries, including inflammation of the quadriceps tendon just below the kneecap.

A femoral bone contusion is a deep bruise, or hematoma, of the thighbone. Contusions of the femur can occur from extreme blunt trauma to the thigh or from the femur jamming the tibia at the knee joint, which might happen if you landed awkwardly from a jump.

If you are an avid runner, you may be well acquainted with annoying aches and pains. However, pain in the medial collateral ligament -- the thick band that supports the inside of the knee and attaches the femur and tibia -- may be indicative of a serious injury.

The knee joint connects the upper leg to the lower leg and is used during many physical activities throughout the day. Overuse, however, makes the knee joint prone to inflammation, which can cause pain in a patient.

Cartilage acts like a pad or cushion, protecting your bones at the joints during movement. In older adults and younger people who are very physically active, like athletes, cartilage may start to break down and become less cushiony over time.

As anyone who has ever been pregnant, or has known a pregnant woman, knows quite well, pregnancy can put a great deal of stress on a woman's body. Not only does her weight increase--sometimes dramatically--but her center of gravity shifts. Further, her joints soften in preparation for delivering a baby.

Running provides a great aerobic workout that boosts energy and metabolism. Unfortunately, it can leave your knees feeling sore. Runners suffer two common painful knee conditions. One is called patellofemoral pain syndrome.

One of the best things you can do for your joints is to exercise them. In fact, a study published in the January 1997 issue of "The Journal of the American Medical Association" found that resistance exercise significantly reduced arthritis pain in the knees.

Knee pain can be frustrating for weight lifters since it can bring your workout routine to a stop. Due to the excess force you place on the knees during weight lifting, knee pain is a fairly common complaint.

Because of their anatomical location, the testicles are highly sensitive and prone to injury. Runners and other athletes are at an increased risk for groin strain, direct trauma and other injuries that can result in testicle pain.

Running offers benefits to your body, such as strengthening your heart and lungs and burning calories to help you maintain a healthy weight. But running can take a toll. The repetitive strain on your body, starting from your feet all the way to your lower back, can cause aches and pains.