Hi there, my son is a very active footballer. Over the past few weeks he has been experiencing swollen knees after a training run or game. The knees will swell up and feel heavy. When the swelling goes down there is a tightening in the front and there is pain at the front and bottom of both knees. The swealing will go down after a fairly short period. He will still feel stiffness in the knees. Despite the discomfort he is able to play competitively but the swelling will be evident after the game. He is 13 years of age. Last year he had a lot of trouble with pain in his heels and that had to be managed.
Hi, I had gone through your question and understand your concerns.  According to the information provided, exercising harder than usual or experiencing muscle fatigue can cause cramps and pain. Also, few causes could be long-standing, sitting, running, heat with physical exertion, burns,any allergies or lack of diet or any injury. I would recommend you to see an orthopaedician or a physio doctor to rule out the condition. Hope this helps.