Abstract: At approximately 7:00 a.m. on October 1, 1997, Employee #1, a chain puller in the planing department of a major sawmill, was pulling lumber and stacking it by length. He started pulling off greater amounts with each motion, and was stacking three 8 ft long by 1 in. wide by 12 in. tall boards at once when he twisted his back. He immediately experienced back pain but finished his shift. Employee #1 then took a sick day and returned to work on limited duty, but the problem continued. A medical exam and an MRI revealed a ruptured disc. He underwent back surgery on October 22, 1997, and was released from the hospital two days later, followed by several weeks for recuperation. In the period leading up to the accident, Employee #1 apparently thought he was falling behind in pulling lumber off the chain.