Does the bike helmet prevent brain damage?

Bicycle helmets can reduce minor head damage, but can not prevent serious brain damage. Canberra team leader said he did not deny the helmet to help prevent scalp injury such as scalp abrasions and lacerations; with a hard shell helmet to prevent skull injury, which helps to prevent brain damage.
But most of the current application of the helmet are soft shell, so that the ability to prevent head injury to become a problem. As a measure of road safety, many countries around the world are using adult and child helmets. Australia was one of the first countries in the law to force cyclists to wear helmets, beginning in 1992.
And so on the 16 trials of brain injury occurred in the mechanism of a serious study to analyze whether it is due to skull fracture or angular acceleration (brain tissue rotation and sliding along the skull side) caused. He said there is important scientific evidence that angular acceleration is the main cause of brain damage, but most helmets are designed to resist linear acceleration. Linear acceleration, the external force caused by the rapid acceleration of the skull, the impact of the recent brain tissue. According to the above theory, to protect the brain tissue, helmet should be able to absorb part of the impact energy, reduce the rate of reduction. The current design and testing of standard helmets still follow the untrustworthy theory that linear acceleration is the main cause of brain damage, but ignores the angular rotation.
The soft helmet closes against the crust, causing the head to rotate and produce strong angular acceleration. Bicycle helmet designers do not consider lowering the angular acceleration, which is the main cause of brain damage. But the road safety experts do not agree with the idea, insisted that the helmet is reducing the incidence of bicycle-related brain injury. The British Royal Institute of Incident Prevention said the Department of Transportation recently issued a comment that concluded that all available research data concluded that helmets help protect riders, especially children. He said that in any sense, the helmet is not the most important security measures, but the effect.