Automatic Emergency brakes have unnecessarily or prematurely activated on 2 separate occasions causing my car to stop very abruptly which has resulted in Neck, Shoulder and back pain. I have been very lucky in the recent past and today that a vehicle was not directly behind me. The seat vibrated first when it sensed the car ahead was breaking. When I started to break, the emergency break kicked in. I did not report this the first time because I thought the car was doing what it was supposed to do. Today was unnecessary. No accident and no police report. I do plan on telling the dealership.