## Thursday, December 8, 2016

### #FreeMcDavid

In all contact sports, there is risk of head injury, and professional sports in the last 5 years have implicated new rules where “concussion spotters” evaluate hits where head contact was made. They then decide whether or not the player must leave the playing surface to be evaluated further. Ice hockey is no exception to this sport, and on Monday night one of the NHL’s up and coming stars, Connor McDavid, took a fall and hit his chin on the surface of the ice. He was required to leave the ice, and the Oilers ended up wasting a crucial power play opportunity without their best scorer on the ice. Today, we will explore whether or not McDavid should have been removed from the ice for concussion protocol. The average mass of a human head with the average mass of a hockey helmet is 5.91 kg. Using the conservation of energy equation: ΔKE= - ΔPE + Wnc, we can find that the velocity of McDavid’s head was traveling at 5.94 m/s, using McDavid’s height, 1.8 m. From here, we can use the expression: sum of F=  Δp/ Δt. Initial velocity is the velocity calculated previously, and final velocity is zero. If we estimate the time of the collision to be over the course of .1 seconds, the calculated force exerted on McDavids head is 351 N, or 35.8 g’s. The average human head can withstand up to 95 g’s before becoming concussed, so McDavid, as he claims, should not have been taken off of the ice for concussion protocol.