I ruined my knees years ago falling and bashing them three times, and then not dealing with it. Now I'm going to pay the Piper in a few weeks at the knee doctor. If there's an underlying problem, then get it fixed.
Otherwise, a good soak in a hot tub followed by a soak in cold water will help strained muscles relax. I do this three times a week, evenings, at the Y, and other than being tired from swimming for an hour, everything seems to feel and work much better.
There's no dealing with the knees anymore......arghhh! Now I do container gardening on my deck and hire the yard work done. I point and he digs! :-)