The International Ice Hockey Federation recently completed a seven year study that determined there were fewer concussions, a 29% lower risk of injury, and a 60% lower risk of shoulder injury at arenas using flexible boards and glass.
For additional information and the IIHF News Release, See: IIHF Media Release, and the complete IIHF study can be found at: IIHF Flex Boards Study OCT 2014.pdf