Operate drills, drivers (for screws and other fasteners), riveters (pistol grip, pop, mashers, squeezers), impact wrenches, nut‑runners, saws, and grinders. Stand and move on concrete for 8–12 hours; see, walk, bend, reach, grasp, stoop, kneel, twist, crawl, carry, climb ladders, work overhead, push, and pull.