It is sometimes hard to have a first idea of how far to place an object in a 3D when designing workstations.

For example, let say that you want to design a workbench. What should be the distance for the worker to access the tools?

On one hand, we want enough work space on the table, but on the other hand, we want to be able to reach for the tools.
The ISO 14738 standard provides us easily calculable optimal hand zone, which limit the risk of MSD.

Using a 50 percentile American male (average size male), We have a limit reach distance of 485 mm.

For 5 percentile American female (small woman), the reach distance limit is 402 mm.

What does this mean?

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.

This is not enough!

This measures gives us an initial idea of how far to approximately place your objects, but this is not enough.

A best way to have a 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.

Considering not only the object height but the manikin whole posture, the joint load considering extremely precise parameter like the task frequency, object weight, etc ...