Describes basic concepts in epidemiology such as incidence and prevalence and statistics such as odds ratios (ORs), relative risks, and positive and negative predictive values (NPVs). Common work-related musculoskeletal disorders (WMSDs) are described with their corresponding anatomy. A risk assessment tool, the Strain Index (SI), is described with a worked example and the cost effectiveness of WMSD prevention programs is reviewed using case studies from the literature. Material on the increasing use of cell phones and tablets is reviewed. A checklist for the assessment of repetitive tasks is included in the chapter. Comprehensive guidelines for the management of WMSDs at work are given.