Hi dr.  My 18 year old daughter jumped on my back, I wasnt standing straight and went down on one knee.  I seemed to have over extended it as I fell.  The pain was excrusiating but soon got better.  By the next day I could hardly stand on it, it was swollen.  I have been limping for a week and it hurts to bend it.  Also it seems to lock in the mornings or if I sit for a while I cant put too much weight on it.  I have tried ice, hot baths, and even a heating pad but I still have pain.  What should I do?
It seems that you have an injury to meniscus or cruciate ligaments. Best thing to do is application of ice, anti inflammatory medications rest and examination by an orthopedic surgeon. You can directly go for MRI after a week or so to get confirmed diagnosis.