I get the jerking of my right leg when standing, but so far only when in the shower. This is due to my MS.
The only thing I can think of regarding the hand shaking when exercising your leg is that you might be using the hand as a counter balance during the exercise. This could account for the tremors in the hand in the same manor as when reaching.
I also get tremors in both hands due to my MS. My Neuro just started me on Gabapentin and baclofen and I have noticed that my hand tremors have stopped. I'm not sure which medicine is the one that is providing the result though.
Dennis
My whole left side shakes when I lift my left leg. I think it's a balance thing, like my arm and shoulder have to compensate when I have to focus so hard on staying upright.
But then my arm/hand on that side tremor most of the time anyway. It's just more pronounced when I try to do something my body has trouble doing these days. Like a full body intention tremor, LOL.
Best of luck to you -- I'm looking for dx still too.
I'm on gabapentin and flexeril. I just thought it a strange cross over reaction. Thank you both for sharing.