You are getting pins and needles in your arms and fingers when arms slietly bent for short period of time?

The "pins and needles" feeling is a result from a lack of blood supply to the nerves that service the affected region. Often times this is a result of crossing your knees for too long while listening to a boring lecture in class, or from crouching too long, trying to get that gum off of your shoe. My least favorite is from actually falling asleep in a strange position. When you wake up, your nerves are so starved for an adequate blood supply of oxygen and nutrients that they take at least a minute for full sensation and control to return. :P