San Antonio Silver Stars guard Becky Hammon warms up before the game against the Washington Mystics at the Verizon Center in Washington, D.C., Thursday, July 29, 2010. (Chuck Myers/MCT)

Doctors warn that heading the ball can increase the chances of CTE. (Chuck Myers via MCT)

Jeremy Lin has been the catalyst behind the Knicks 6-game winning streak. (Chuck Myers/MCT)