In 2004, the Transport Research Laboratory (TRL) published TRL Report 614, Impact of Road Humps on Vehicles and their Occupants (available via the TRL website at www.trl.co.uk), which was commissioned by the Department for Transport.
The report concluded that for vehicle occupants levels of discomfort were, generally speaking, acceptable if speeds did not exceed 15 to 20 mph. Expert medical opinion following this research was that damage to healthy bones, discs, ligaments or muscles was very unlikely. It was noted that excessive exposure to repeated loading from humps could lead to the prolapse of an unhealthy disc. However, “excessive exposure” would have to be more than that expected from even a busy taxi driver in an urban environment.
We have no evidence of specific hazards relating to people with other sorts of spinal injuries.