The libraryStrength

Motorcycle riding

A helmet takes 42 percent off the risk of dying and 69 percent off head injury.

Also called Motorcycling, Motorcycle crash risk, Motorcycle helmets, Powered two-wheelers

Who it's forAny man on two wheels, and the one getting back on at 55.

The item

Three squares: proven in human trials. Two: a strong signal. One: early human data. Striped: the trials disagree.

Emergency: call 911.

I am not a doctor. This is not medical advice. This is self-education. Talk to a physician who has your history before you change anything.