Drywall workers compensation claims often involve low back or neck injuries. Drywallers injure their lumbar and cervical discs from job duties over time and from single traumatic incidents. Drywallers apply plasterboard or other wallboard to ceilings or interior walls of buildings as well as mounting acoustical tiles or blocks, strips, or sheets of shock-absorbing materials to ceilings and walls of buildings to reduce or reflect sound. Materials are often heavy but it is the awkward positions drywallers are required to work in that often cause or contribute to the herniated lumber or herniated cervical discs, resulting fusion surgery. Specialized drywallers include lathers who fasten wooden, metal, or rockboard lath to walls, ceilings or partitions of buildings to provide support base for plaster, fire-proofing, or acoustical material. Plasterers apply coats of plaster to interior walls, ceilings, and partitions of buildings, to produce finished surface.