Why traumatic brain injuries raise the risk of a second, worse hit

Slowed reaction times, dizziness and double vision confound a quick-moving quarterback

Tua Tagovailoa, wearing a teal jersey with the number 1, tries to throw a football amid a tackle

When he got sacked on September 29, Miami Dolphins quarterback Tua Tagovailoa (teal uniform, No. 1) sustained a head-rattling concussion. His injuries have reignited discussions of brain safety for professional football players.

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In a football game on September 25, Miami Dolphins quarterback Tua Tagovailoa got the pass off but he got knocked down.