Arthritis is the group of conditions which involves damage to joints characterized by swelling and severe pain cartilage thins and reduce the ability of tissues to stretch and reduced production of synovial fluid in the joint capsule. chondromalacia patella is an abnormal softening of the cartilage of the under the knee cap (patella)characterized by knee pain. bursitis: it is an inflammatory condition of bursa characterized by pain and swelling. collateral ligament tears/sprains: these ligaments supply stability to your knee for side to side movement and even during normal walking. injury to these areas usually occurs after strikes from the side such as a football tackle. the pain is usually located over the sides of your knee and is worse during any activity and is better with rest. swelling can be anywhere from very mild to quite significant. flamingo knee cap gives you great relief.