I am 52 yrs old tennis lover. Few months ago, I got sudden right knee pain as I was hitting tennis ball with boy rotation. pain subsided after rest for few days. pain came back again after more hitting (I thought maybe recovered). pain last longer and knee starts swell mildly. MRI knee shows effusion, some edema in femur head and mild degenerative changes. also mild edema in soft tissue above knee joint. pain is lessening a lot, but knee swelling persists. no tennis for 2 wks. should I still use ice or heat at this point? when knee swelling or effusion will go away? should I do some light activity such as walking? many thanks.