Behind the Knee Pain Posted January 8, 2015 by Jack Armstrong Behind the Knee Pain? It might be Chondromalacia. Chondromalacia patellae is the condition that describes the softening and fraying of the underside of the kneecap. The undersurface of the kneecap ( patella ), is covered by a smooth layer of cartilage. This cartilage normally glides easily across the knee when the joint moves. In fact, the undersurface of a healthy kneecap is generally several times more slippery than ice! In some people, the kneecap can rub against one side of the knee joint, which overtime causes wear and tear and leads to irritation. Left untreated, the cartilage will fray, which increases the friction between the undersurface of the kneecap and the knee. Many people with chrondromalacia can describe the feeling when they bend the knee as a crunching/crackling sensation ( think snap, crackle, pop ). In some cases, you can actually hear a crackling sound when the person bends his or her knee. Often, there is little pain associated with this. The pain is actually caused by the inflammation and irritation caused by these small pieces of cartilage breaking off settling within the knee. This is often the reason why some patients don't tend to have too much pain while undertaking a particular activity, but really feel the pain a day or two later. If you have chrondomalacia, the recommended treatment is to rest the knee until the pain goes away. Pain is your enemy. Remember, if you are experiencing pain, that means that tiny pieces of you kneecap have broken off and you've done some damage. The next step is to figure out why your knee has been damaged. As said above, the cause is generally the kneecap not tracking properly. The reason for this varies, but common reasons include imbalanced leg muscles ( e.g. the outside muscle of your thigh pulls harder than it should, yanking the kneecap off track ). This is where a good physical therapist can really come in handy!