Monadnock Ledger-Transcript Published: 6/14/2017 10:27:10 PM In 2012, Shawn Hiers, 43, of Peterborough, was working as a machine operator at New Hampshire Ball Bearings, and was on break when he fell and struck his head on concrete and suffered a traumatic brain injury. “Both feet just went out from underneath me. At first, we didn’t know what had happened,” said Hiers. “First, they thought it was a concussion. Then post-concussion syndrome. It took eight months to be diagnosed as a traumatic brain injury.” In some ways, said Hiers, it’s an invisible injury. He can walk, and talk and interact with people. In other ways, his life was completely changed.