Hi bghouse,
Pins and needles sensations are usually caused by lack of circulation which is most often pressure points but could also be from joints that are not inside their “neutral” range of motion and are restricting blood flow (like arms and legs that fall asleep when they are in a stressed position for a longer period of time).
Post #2 here and the posts it links to may be helpful with the “detective work” that is often necessary to track down the source of any discomfort or pain you are having on a mattress. 
I wish it was easier but our bodies are very complex and individual it’s a lot like trying to “diagnose” a medical issue over the internet without being able to see someone in person.
Phoenix