I have a sharp, pin prick-like sensation in the same location from time to time recently in the upper left part of my back. It s not constant but it is in the same spot. I had my wife look at it and she did not detect anything unusual about it. I thought it might be a splinter from something but I don t remember doing anything in the area of my back that would cause this type of pain. I was involved in a severe industrial accident where I ruptured the quadriceps tendon at the kneecap on both of my knees. I have painful neuropathy in my toes due to that. Any suggestions as to what s causing the single pin-prick in my back and what to do about it?