Postero-medial Incision Placement in Brachioplasty

I think the most important part of arm lift scar management is dealing with the scar redness and thickening that often develops in these patients. The scar should be positioned beneath the biceps muscle in the groove along the inside of the arm. More posterior placement risks migration of the scar onto the back of the arm, where it is always visible.

I think you're getting caught up on terminology.
Think of it this way. Do you want your scar visable when your arm is raised or do you want the scar to be only visable to people walking behind you? I don't think theres a single "right" answer...
Just to warn you... both locations tend to give heavy and noticable scars. This is NOT a procedure to enter lightly or without consideration (not that any procedure is).