Antenociti’s Workshop have posted the concept art for some G.O.T. Power Assisted Armour figures.
From their website:
Power Assisted Armour Concept Art for the G.O.T standard Trooper.
The PA armour is mainly used by troops carrying additional loads such as heavy and extra-heavy weapons, but can also be used in high-G environments. It feature some additional armour but its main function is to augment strength.