We all know that standing up and playing is a lot more difficult than sitting down and playing... the thing I find the most difficult is playing in the upper register of frets on the low E string. That stretch for the fingers is killer. The biggest problem is trying to do a 3 finger stretch across like 6 frets on the low E string while standing up. Anybody have any suggestions for stretching exercises to get used to this so I don't pull a tendon in my arm?