Musculoskeletal load in and highly repetitive actions of animal facility washroom employees.

Regular work tasks in the washroom of laboratory animal facilities include cleaning of cages and bottles and handling of chow and bedding. These operations largely are carried out by hand. We quantitatively determined the musculoskeletal load on the trunk and upper limbs of washroom employees in an animal facility with a holding capacity of 35,000 rodent cages by using a computer-assisted, quantitative, recording, and long-term analysis (CUELA) system, which volunteers wore during routine work. Parallel video recording allowed exact assignment of each movement of body and limbs to the data recorded by the sensors. For the most part, trunk movements were unassociated with risk of injury. Evaluation of upper limb movements by CUELA indicated elevated burden on shoulder, elbows, and wrists due to the high repetitiveness and range of movements and postures. However, after additional work factors like low effort and the presence of micropauses were taken into account, workers were not at risk for the development of musculoskeletal disorders of the upper limbs. Handling bottles, chow, and bedding and maneuvering trolleys that entailed greater musculoskeletal loads did not yield evidence of overstraining, because the actions typically were executed alternately and were of short duration during daily shifts. The results represent quantitative information on the musculoskeletal load of regular washroom operations in a laboratory animal facility. These data provide the basis for ergonomic redesign of operations and implementation of automation for highly repetitive movements.