Woah! Weird Feeling in Hand

[kingofclutch]

So I was using the arm up technique for the first time. I can't find the thread about it so I put my arm up at a 90 degree angle and lied down on my side. That was my left arm. I let my hand hang down. Then my right hand started to get a little numb and so did my feet. Then around 5-10 minutes later I felt this pressure on the outside of the hand(opposite side of palm) and then about 30 seconds later underneath my hand or on the palm I felt these waves of pressure on my hand for about 2 minutes and then it went away. I felt a slight pain after and then I put my arm down. Was this part of SP? Or was it something different?