While some riders claim that motorcycle helmets can break necks during a crash, a University of Wisconsin-Madison study shows they have the opposite effect.

Nathaniel Brooks, MD, a UW Health neurosurgeon, looked at the outcomes of 1,061 motorcycle crash victims who arrived at University Hospital’s Level One trauma center between January 1, 2010, and January 1, 2015. Wisconsin law doesn’t require helmets for most motorcycle riders, and so fewer than a third of them, or 323, were wearing helmets at the time of their crashes.

The riders who did not wear helmets had twice as many injuries to the cervical spine, commonly known as the neck. The study found that 15.4 percent of riders without helmets received at least one cervical spine injury compared with 7.4 percent of those wearing helmets.

In addition, those without helmets had more than twice as many cervical spine fractures: 10.8 percent of the helmet-less riders broke a bone in their neck, compared with 4.6 percent of those with helmets. Ligament injuries to the neck were also more common without helmets.

While helmets have been documented to save lives, and decrease traumatic brain injury, some opponents of helmet laws have argued that they are more likely to cause neck fractures.

“Our study suggests that wearing a helmet would be a reasonable method to reduce the risk of cervical spine injury in a motorcycle crash,’’ says Brooks, an associate professor of neurosurgery in the UW School of Medicine and Public Health.

His co-authors are neurosurgery residents Paul Page, MD, and Zhikui Wei, MD. The study is being published this month in the Journal of Neurosurgery: Spine.