Shaking REM and movement

i Wanted to know what kind of experience i had today while i meditated. I meditated after a long time and it lasted 1,5 hours. I started shaking after a while, then twitching my eyes, REM and after some time i started moving.. It was n a rythm. sometimes sideways, sometimes down towards the floor and so on. And when i wanted to stop my meditation i came back to my first position, then shaking, eyemovement, twitching and back to normal. Did something like this happen to anyone? Is it a good or a bad sign? Thanks :)