Vieira ER, Kumar S, Coury HJCG, Narayan Y (2006).

Low back problems and possible improvements in nursing jobs.

Journal of Advanced Nursing, 55 (1), 79-89.

This paper reports a study that aimed to evaluate the workload, to identify problems leading to the higher incidence rate of work-related low back injury among nurses in the orthopaedic and intensive care unit departments and to gather information about improvements that the nurse would like in the workplace. 

Also, check out this article at: http://www.metropolitannurse.com/moxie/industry/workrelated-low-back-diso.shtml