METHODS:
We analyzed 1896 female RN and NA, who were free of shoulder pain in 2006 and in the same position and work unit in 2008. Incident shoulder pain (SP) was defined as self-reported pain that persists for ≥4 days and/or increases during a lateral movement of the arm away from the midline of the body (abduction). Both cross-sectional and longitudinal models were built to test if work-unit-level features or their influences on both work tasks and individual perception of the work environment directly influence the risk of developing incident SP.