2 EEs & Foreman were making a splice in #1 Belt. They were using two 1 1/2 tons chain hoists to pull belt back together. 1 man on each side of belt with 1 man operating each hoist. Belt was almost back together when EE stopped ratcheting the hoist & said he'd done something to his rt shoulder. This happened 7/12/10, he worked thru 7/24/10, went to dr & didn't come back to work.