leg trembling/ sewing machine legs

I must thank you for the informative forum. I experienced sewing machine leg today while trying to drive home from a particularly gruelling hike (because I am so not fit enough) and i couldnt get my foot to stop shaking unless i pressed the heel down. It seemed very odd, my hubby was worried, and I thought that I was finally going into shut down mode. I normally get severe shakes from my asthma meds, and these scared the bejesus outta me. I could also picture my GP telling me that it was all in my head. How nice then to find a perfectly plausable explanation!It was especially scary since I was not able to maintain the revs on my car because it was my right leg that I use for the clutch and it refused to stay still! I got home in one piece though.
Thanks again. :smack: