Skin between pecs and arms at armpit folds over twice?

Question

The area around my armpit (between my chest muscle and arm) has 2 folds (instead of 1) (as seen in this picture (NOT OF ME):http://home.columbus.rr.com/zxcvbn/ab2.pecs.JPG) Would this be because of just doing flat bench press and NOT doing incline or decline?

Answer 1

Broken link, but most likely. It's because all your muscle in on your front, what your doing is actually dangerous. Someone a fourth of your size could easily dislocate your shoulder.

EDIT: If all your doing is flat bench then your pecs and shoulders are getting strong sure, but your upper back and shoulders are small and weak, meaning all the muscle is being pushed back by the muscle on your front. Your shoulder can come easily dislocated because of the way your muscles have formed so one-sided.