The answer is 0 MPH, as it's not your vehicle's speed, but somewhat the main difference in velocity in between your vehicle and whatever else It truly is colliding with that could cause the injury. Based on Collision Masters, frame problems can manifest in accidents as slow as 30 https://myleskmnnm.magicianwiki.com/8580175/indicators_on_my_car_frame_bent_you_should_know