Dystonia can be very unpredictable. I can get dystonia in certain muscles during Sinemet peak-dose, that I don't get during "offs".

Last evening we went for a walk around the neighborhood and suddenly my left foot started cramping and my knee turning outwards, so that I could hardly walk. This was prior to dinner, I was maxed out on levadopa, and the only thing I had eaten an hour earlier was a banana.

You would think this to be an optimal condition to do some light exercise. You would think the potasium in the banana would be good for your muscles ... well, PD does not submit to the logic of a healthy metabolism and it just might have been too much, who knows?