Can you sleep on your back?

I had a sleep study last night.  I have episodes of kicking in my sleep that we are trying to figure out.  It was a different evening, going to the hospital and "checking in".  The paper work I got for the sleep study said it was like a hotel. I'm not sure I'd call it a hotel, but it was nicer than a normal hospital room.  As I was trying to fall asleep (actually almost asleep) the technician came back in and asked if I could sleep on my back.  I told him I probably wouldn't stay that way, and he said it was ok, if I could just go to sleep,on my back... Turns out, I can't go to sleep on my back 😝