1. Liberty Mutual Research Institute for Safety: Liberty Mutual Workplace Safety Index. Liberty Mutual 175 Berkeley St., Boston, MA 02116 (2014)
2. Luo, X., Pietrobon, R., Sun, S.X., Liu, G.G., Hey, L.: Estimates and patterns of direct health care expenditures among individuals with back pain in the United States. Spine 29(1), 79–86 (2004)
3. Bernard, B.P.: Musculoskeletal Disorders and Workplace Factors: A Critical Review of Epidemiologic Evidence for Work-Related Musculoskeletal Disorders of the Neck, Upper Extremity, and Low Back. U.S. Department of Health and Human Services, Center for Disease Control and Prevention, National Institute for Occupational Health and Safety, Cincinnati OH (1997)
4. National Research Council: Musculoskeletal Disorders and the Workplace: Low Back and Upper Extremities, Washington, DC (2001)
5. da Costa, B.R., Vieira, E.R.: Risk factors for work-related musculoskeletal disorders: a systematic review of recent longitudinal studies. Am. J. Ind. Med. 53(3), 285–323 (2010)