Stagehand - is a person who works in the context of touring concerts or other events to set up a stage himself and/or assists the stage technology and the specialists.
They are also referred to as set-up helpers, stage helpers or simply hands. The stagehands usually only work locally and are not on tour with an artist, which is why they are also referred to as local crew.
It's definitely physical work. You unload trucks, move rollable boxes and help set up sound, light and video equipment.
It is not a profession with recognized apprenticeship training.