Paintball elbows what are you talking about.
Well glad you asked. It is to do with the positioning of your elbows when you hold a paintball gun.
Most beginners and some more experience players tend to keep their elbow’s out generally because most hunters and clay target shooters hold their rifle / shotgun to get extra swing, and on tv, movies you see this a lot.
However extruding elbows or wings which presents a greater target for them to be hit.
If you see and special forces videos, they are trained to keep their elbows in.
So, if you want to be less of a target and look rock solid keep those elbows in when playing especially when firing and yes that is both elbows keep them in.