Helmets are a valuable tool but no panacea unfortunately. Best to never have to find out how much protection they actually provide. But anyone who thinks
You'd be surprised. The current standards helmets are tested against still only use ~15mph as the testing guideline for providing protection. G forces
The point is that everyone should wear a helmet and it will help in many circumstances but a helmet does not protect one very well if a tree is hit at
You're citing a book which was published 10 years ago? Helmets and research have gone a long way since then.
The logic is in a study on the topic written by experts on ski safety (including a professor from Rochester Institute of Technology...my alma mater!):