From 2022 Canadian children aged 12 and younger will no longer be able to play the fullest version of American football to protect them from long-term cognitive problems resulting from repetitive head knocks, while in the US Massachusetts has become the seventh state to consider banning American football for children.
Should New Zealand follow suit in the case of rugby? Dr Bob Cantu is America's leading expert on athletic brain trauma.
Dr. Robert Cantu is the chief of neurosurgery and chairman of the Department of Surgery at Emerson Hospital, and co-director of Boston University Center for the Study of Traumatic Encephalopathy.
At his practice at Emerson Hospital, he treats hundreds of patients a year for concussions suffered while playing sports.