Doctors see increase in hospitalizations, injuries from electric bikes

There's been an uptick in use of electric bikes on Bay Area streets over the past few years. At the same, fewer people are wearing a helmet when they ride, which experts say has led to an increase in injuries and hospitalizations. Kevin Li, from UCSF School of Medicine, is a co-author of a study that looked at these issues. He joined us on 'The Nine' to talk about the biggest takeaways.