Osteoarthritis is the most common type of knee arthritis. Also called wear-and-tear arthritis or degenerative joint disease, osteoarthritis is characterized by progressive wearing away of the cartilage of the joint.
Iliotibial Band Syndrome is irritation / inflammation of the iliotibial band (the inflammation is usually not visible) that causes lateral knee pain. This condition is most common in long-distance runners and cyclists.
Muscle Strains Increasing the duration and intensity of exercise or any activity too quickly often causes muscle strain.
Knee Bursitisis a sac containing a small amount of fluid that is located between surfaces that need to move to reduce friction. Bursitis (Inflammation of a bursa) is usually caused by overuse. Excessive kneeling often causes prepatellar bursitis (common in carpet layers, gardeners). The symptoms are knee pain and inflammation over the kneecap and sometimes limited range of motion.
Tendonitis of the KneePatellar Tendonitis (also called jumper's knee) is generally caused by overuse of the quadriceps, especially jumping types of activities such as volleyball and basketball. Quadriceps Tendonitis is also generally caused by overuse of the quadriceps.
Meniscal tears may occur during participation in sports, often when the knee is twisted.
Torn ACL The knee may give out suddenly when the ACL is torn and there may be a popping sound upon injury. Symptoms of a torn ACL include knee pain, swelling, stiffness, and bruising. Walking is painful and the knee feels unstable.