March 2017 Newsletter:

Getting into Your Comfort Zone - Working Heights

This old expression has a very literal application in ergonomics: when working, your posture affects both comfort and injury risk. Generally, the closer you can be to a neutral standing or sitting posture, the less chance you have of being injured. Deviating from this posture makes your muscles work harder, which can tire them out and cause soreness. Over time, this can wear down tissue and lead to injury.

When fitting a workstation to a worker, there are several factors that should be considered: one of which is the height of the work surface. This varies depending on the nature of the task being performed. For normal work tasks like light assembly and typing, the work surface should be in line with the worker�s elbow. This keeps the shoulder and wrists as relaxed and neutral as possible when working. When doing heavier work, where lifting or a downward force is required, the work surface should be kept below elbow height. This allows the worker to engage the muscles of the lower body when lifting or pressing, and spares the shoulders and arms from doing this heavy work. For fine motor tasks, like electronic assembly, where workers must look closely at what they�re doing, the work surface should be at chest height. This will allow workers to examine objects without leaning forward too much.

Equally important to the height of the work station, is the distance from the work surface to the worker. To promote a neutral standing position, objects that are used regularly by the worker should be kept less than one forearm�s length away. This will allow the worker to easily access their materials without bending forward at the waist or reaching out with the shoulder. Additionally, workers should always try to stay as close to their work surface as possible, again to try and minimize forward leaning and reaching.

It may seem daunting to try and tackle these problems; assembly lines and heavy machinery often appear difficult to modify. Here are some simple suggestions that can act as a first step towards improving workstation setup:

  • Look for surfaces that can easily be changed (e.g. inspection tables or work benches)
  • If the surface can�t be moved, move the worker (e.g. provide a step for a short worker or a high chair for a tall worker)
  • Get rid of unused space (e.g. use a smaller work surface to prevent reaching)

Ideally, work surfaces would be fully adjustable so that they can be fitted to the present worker. If this isn�t the case, however, always keep the ideal working heights and distances in mind when looking for solutions. Sometimes a small change can make a world of difference.

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