Weiss Tech Sound Bytes

A 2010 study from the Mayo Clinic reports that NCAA Men's hockey players experience 46% fewer concussions than their non-checking counterparts, NCAA women's hockey players. How is this possible? If it's true, why is checking and fighting being attacked? Here the link to the article referenced in the soundbyte: http://slapshot.blogs.nytimes.com/2010/10/19/at-the-mayo-clinic-womens-hockey-a-most-dangerous-game/?_php=true&_type=blogs&_r=0