motorcycle helmets - choose a jigsaw puzzle to solve

A motorcycle helmet is a type of helmet used by motorcycle riders. The primary goal of a motorcycle helmet is motorcycle safety - to protect the rider's head during impact, thus preventing or reducing head injury and saving the rider's life . Some helmets provide additional conveniences, such as ventilation, face shields, ear protection, intercom etc. Motorcyclists are at high risk in traffic crashes. A 2008 systematic review examined studies on motorcycle riders who had crashed and looked at helmet use as an intervention. The review concluded that helmets reduce the risk of head injury by around 69% and death by around 42%. Although it was once speculated that wearing a motorcycle helmet increased neck and spinal injuries in a crash, recent evidence has shown the opposite to be the case, that helmets protect against cervical spine injury, and that an often-cited small study dating to the mid- 1980s , "used flawed statistical reasoning".