I HAVE BEEN HAVING SHARP PAINS BETWEEN MY SHOULDER BLADES LATELY OFF AND ON FOR A WEEK OR TWO. THEY JUST COME AND GO . FOR EXAMPLE ,I WILL START START TO TURN TO WALK INTO ANOTHER ROOM AND IT WILL HIT ME OUT OF NO WHERE, BUT IT SHARP AND PAINFUL ENOUGH TO STOP DEAD IN MY TRACKS.THEY DON T LAST LONG MAYBE TWENTY OR THIRTY SECONDS. BUT I GET THEM QUITE OFTEN AND AT TIMES I CAN FEEL THE PAIN ALL THE WAY THROUGH TO MY CHEST. I HAVEN T LIFTED ANYTHING. SO I KNOW IT S NOT AN INJURY. ANY IDEA WHAT COULD BE CAUSING THIS?