I have it in my legs mainly, but occasionally in my arms as well. I was started on Baclofen, and am seeing good results so far.

It happens to me too

Yes. I have it mostly in my triceps, biceps, and sometimes (but much less) the side of my chest.
I was prescribed 30mg Baclofen, and although it's helped a lot of Msers, it wasn't very helpful for me, and since it added to my list of like 7 or 8 daily pills, I decided to drop it from the roster a few weeks ago.

I get all kinds of jumps in my sleep. One small spot on my belly jumps hard enough to wake me. My biceps jump. My feet jerk hard in my sleep and often wake me. My arms jerk. It's like the jerk just as you fall asleep only it is tiny areas. I get twitches throughout the day. I never know what will jump next.

I do have that mostly in my legs, and it seems more so at night... sometimes they get really tight and jump and sometimes they just jump. My poor fiance is always getting kicked lol