Hello about two weeks ago I was walking through the house and kind of over walked my step and it felt like the muscle behind the kneecap was stretched. Well it was a little painful but didn't bother me much until two days when I mowed the yard. I push mowed and came inside and the inside of my kneecap on my right leg up into my inside thigh has swollen double it seems. I have propped my leg up, put a wrap on and nothing seems to help. The swelling will not go away and its painful behind the knee. My foot on that side is swelling as well. I am 31 year old male in pretty good shape. What could it be. The pain is not unbearable and I am taking 800 mg motrin twice daily for it. Not helping. Is it something else or worse.