A study reported in the Journal of Neurosurgery (J Neurosurg 120:919922, 2014) evaluated whether helmet design may reduce the incidence of concussions among football players. A retrospective analysis was performed of head impact data collected from 1833 collegiate football players who were instrumented with helmet-mounted accelerometer arrays for games and practices. Concussion rates were compared between players wearing Riddell VSR4 and Riddell Revolution helmets while controlling for the head impact exposure of each player. A total of 1,281,444 head impacts were recorded, from which 64 concussions were diagnosed. There was a total of 322,725 head impacts to players wearing Riddell VSR4 helmets, including 27 concussions There was a total of 958,719 impacts to players wearing Riddell Revolution helmets, including 37 concussions. What is the relative risk of sustaining a concussion wearing a Riddell VSR4 Helmet compared to a Riddell Revolution Helmet? Calculate the 95% condence interval. Relative Risk = 95% Condence Interval Lower Bound = 95% Condence Interval Upper Bound =