Knee injuries are often painful, with swelling around the joint, together with heat and stiffness. This may be accompanied by the knee suddenly giving way or locking.
A knee problem may occur as a result of a sudden, acute, injury, such as a fall, or a violent twisting movement. Other types of knee problems arise over a longer time period, resulting in a chronic injury. This may happen as a result of a pre-existing knee misalignment, which the individual may have been born with, or from over-use of the knee joint. This type of injury can occur when the muscles which support the knee joint, the large quadriceps thigh muscles, are insufficiently developed and strengthened to keep the knee moving in its correct plane when walking or running.
A locked knee requires medical attention to ensure that the correct straightening procedure is used to prevent further damage to the meniscus, or cartilage, which acts as a shock absorber between the upper and lower parts of the leg. Surgery is usually required to repair a torn cartilage.
Both types of knee injury require careful attention to ease discomfort. Young athletes in particular are prone to developing a condition called Osgood-Schlatter disease, resulting in pain just below the kneecap. The condition occurs through over-use of the quadriceps muscle, which then places a strain on the ligament which attaches to the tibia, or shin bone.
Injuries to the knee ligaments fall into the acute category of knee injury and occur when the knee is twisted or over extended; resulting in severe pain and swelling, and the knee is sufficiently unstable to walk without the leg giving way. The most common ligament injured is the anterior cruciate, or ACL as it is known. This type of injury often requires surgery, followed by an often lengthy period of rehabilitation to strengthen the muscles surrounding the knee.