All risk assertions in the initiative have been made using the Prasad/Mertz head injury risk curves. The risk curves cannot accurately predict the risk of injury from an impact. Actual risk of injury will vary from person to person and depends on many factors, including but not limited to the impact velocity, the angle of the impact, the impact surface, as well as the age, weight and physical condition of the rider.
The correlated risk of suffering a skull fracture or fatal traumatic brain injury is reduced to less than 5% according to the Prasad/Mertz risk curves for impacts with a maximum deceleration of 183 g and maximum HIC value of 1666.
No helmet can protect riders from any and all injuries.
When riding, please wear a helmet.