Often insurance adjusters will minimize your claims based on the severity of the property damage. However, property damage is not a reliable indicator of injury, including in low-speed collisions.
Rather, other factors are far more relevant when predicting injuries of a low-speed collision. These factors include, but are not limited to: the ability of the vehicles to absorb/transmit energy, size/weight of the vehicles, size/weight of the occupants, and awareness of the impending collision. Serious injuries have been reported in collisions with minimal property damage. As such, always seek medical treatment if you are involved in an auto collision no matter how minimal the property damage may appear.