August 22, 2022

How Far to Place an Object – The Ergonomic Answer

Have you ever tried to figure out how far to place an object in a 3D? This is an especially good question when designing workstations. For example, lets say that you want to design a workbench. What should the distance be for the worker to access the tools?
Quentin Bourret

Have you ever tried to figure out  how far to place an object in a 3D? This is an especially good question when designing workstations. For example, lets say that you want to design a workbench. What should the distance be for the worker to access the tools?

On the one hand, you want enough work space on the table. On the other hand, you want to be able to reach for the tools with minimum effort.

The ISO 14738 standard provides an easily calculable optimal hand zone, which limits the risk of Musculoskeletal disorders or injuries (MSD). The ISO 14738 standard provides us easily calculable optimal hand zone, which limits the risk of MSD.

Using a 50 percentile American male (average size male), this depicts a limit reach distance of 485 mm. For a 5 percentile American female (a small woman), the reach distance limit is 402 mm.

What ISO 14738 Standard Means

To have a safe and efficient design, your worker should reach objects within 485 mm of distance.

Now if you want to go above and beyond and have a more inclusive design (allowing workers of different sizes to work safely) the limit distance should be 402 mm. In our workbench example, this means reducing the table width between 485 and 402 mm.

Is That Calculation Enough?

This measure gives us an initial idea of how far to approximately place objects, but it isn’t enough. A best way to have a solid estimation of MSD risk is to use Ergonomic Workplace Design​​​​​​​ (EWD).

Thanks to EWD you’ll be able to have an accurate worker posture evaluation in 3D. This considers not only the object height, but the whole manikin posture, the joint load with extremely precise parameters like the task frequency, object weight, etc.

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