Among the causes of knee pain are injuries to the cartilage that sustains the knee, sprained ligaments that will not turn back to its regular form and firmness, a torn muscle, knee joint being dislocated, an inflammation of the cartilage that leads to arthritis, being overweight, and other chronic diseases. The symptoms are not limited to constant pain. Oftentimes there is an obvious swelling, redness, burning sensation, a sharp and shooting feeling of pain when it is being used, numbness, and difficulty in walking or even standing up.