Ice hockey is a team sport, using skates and sticks, where to teams compete in getting the puck into the opponent team's goal. When the game is over, the team scoring most goals has won.
Casey Jones usually uses an ice hockey goaltender's mask of 1950's-60's style, and as a weapon also an ice hockey stick. Even Zach in the 1987-1996 animated series episode The Fifth Turtle fights with an ice hockey stick.
In the IDW continuity, Casey Jones played college ice hockey at New York Tech on a sports scholarship. Because he was underperforming in his other classes at the school, Casey was placed on academic probation, forcing him to seek out a tutor to help him raise his grades. This is how Casey first met April O'Neil, whose tutorship (in exchange for self-defense lessons) successfully raised Casey's grades enough to end his academic probation. But during the City Fall arc, Casey was severely stabbed by the Shredder and needed to be hospitalized for weeks. Casey eventually recovered, but he lost his scholarship, ending his college ice hockey career.