The trainer at our gym taught my daughter to do a barbell curl keeping
the barbell as close to her body as possible throughout the movement.
This means adjusting the elbows backward as the bar is brought up, then
allowing them to come forward as the bar comes back down.
I've never seen this before. I've looked at several form videos online,
and it appears that in most of them, the elbow is stationary and the bar
moves further away from the body at about 90 degrees, then closer again
until the top of the movement.
Is what he's taught her helpful? Is there any danger or disadvantage in
performing the curl this way?