Eleven (11) Physical Demands Descriptions or PDDs have been produced for every trade sector using an international template that documents key job tasks, repetition, force and environmental working conditions. PDDs are used by health care professionals and decision makers to make informed decisions regarding the risk of developing musculoskeletal injury, and return to work after an injury. PDDs have become more important because the WSIB no longer has Ergonomists on staff to visit workplaces and assess job suitability issues that arise when injured workers return to modified duties.