Ergonomics in modern dairy practice: a review of current issues and research needs.

Dairy farming is an ancient occupation. Traditionally, cows have been manually milked while tethered in stalls or stanchions. In the latter half of the 20th century as machine milking emerged, the parlor milking system has become more popular, especially among larger dairy farms. The transition from manual milking to automatic milking systems as well as the transition from stanchion to parlor milking systems involved a dramatic change in milking tasks. These transitions have resulted in changing patterns of occupational exposure to risk factors for work-related musculoskeletal disorders among dairy workers. However, aspects of the milking task such as sanitization of teats, stripping milk from teats, and attachment and detachment of milking equipment have remained relatively the same. Work-related musculoskeletal symptoms have been reported in the low back, shoulders, hands/wrists, and knees. Research that has measured exposures to risk factors for work-related musculoskeletal disorders among dairy farm workers has been limited, especially when using ergonomic tools to directly measure exposure, such as electrogoniometry or electromyography. Self-reported exposure measures have been most commonly used. The interventions that have been tested to reduce exposure to risk factors for work-related musculoskeletal disorders include assisted lift-hold devices, use of lighter-weight equipment, adjustable flooring, and use of rubber mats. However, research evaluating potential solutions to reduce dairy farm worker exposure to risk factors for musculoskeletal disorders is scarce. Future research efforts should further characterize hazards while simultaneously testing viable solutions that fit within the business model of the dairy farm industry.