The driver's seat active head restraint spontaneously deployed. There was no collision of any kind. This occurred while vehicle was stopped at a traffic light. The driver (who is not the individual filing this report) suffered a sore neck as a result. At time of deployment, the driver's head was inclined forward and tilted down. Otherwise the injury might have been much worse. This incident could have been exceptionally dangerous if the deployment happened while vehicle was moving. As of today (June 2, 2022), the vehicle has not been inspected by dealership. The first available appointment for repair is June 8, 2022. No warning or other indication given prior to spontaneous deployment. The part is available for inspection by NHTSA, at least until it is taken to dealership. I have uploaded pictures of part.