Why does my knee hurt a lot when I jump high?
My knee hurts on my left knee on the tip of the leg bone. After a long time of not using it. It hurts again a lot for a day or so when I jump high. Then after that it hurts when I run or jump or kneel. Then I may rest for a long time not using it. I can run and kneel on it and moderator jump, but when I jump high again it hurts a lot for a while. I play sports a lot and like to play without my knee hurting.
I would suggest that you go see your primary care doctor about this issue. It sounds like it is a long standing issue, and you need to have your knee evaluated to make sure there is no serious injury to your knee that needs treatment. In the meantime, you are doing the right thing of trying to avoid strenous exercise when the knee is hurting. One likely possibility is that you have a condition called patello femoral pain syndrome, or "runner's knee." This is a condition in which the knee cap does not track well over the underlying leg bone, which leads to some breakdown of cartilage, causing pain with exercises especially those that bend the knee. The primary treatment for the condition is rest. However, quadriceps strengthening exercises (without bending the knee, like leg raises) are also helpful. There are other causes of knee pain as well, such as damage to the various ligament structures which surround and support the knee. Your doctor will be able to assess for the presence of any of these conditions with a good physical examination of the knee, looking for any signs of localized pain or weakness, and then will be able to recommend treatment.