Evaluation of work-rest schedules with respect to the effects of postural workload in standing work.

The influence of four work-rest schedules (60-min shift-15-min break, 45-15, 30-15, 30-30) on acute effects of physical workload in the back and legs due to standing work was investigated in 12 poultry inspectors. Subjective discomfort in the legs and back, and swelling in the distal lower leg were significantly affected, with the 60-15 schedule leading to a higher postural load as compared with the other schedules. No effect on spinal shrinkage was found. It was concluded that the 60-15 schedule should be avoided. An optimal work-rest schedule considering visco-elastic deformation of the spine would probably involve frequent short breaks, whereas longer breaks would seem more effective considering leg swelling.