[dx034]

Does that mean that lowering your arms with the vest becomes harder? In that case it'll probably take workers a while to build new muscles? Or how does the vest distinguish holding body weight vs the worker lowering their arms.

[Retric]

This gets complicated because you can vary the amount of support based on the angle the arms are at. Anyway, there is no need to account for extra weight simply supporting someone's arms can make a large difference. But, you get into a lot of trade offs.