In training, it's about what you do and what you don't do.
Poor movement begets negative tissue/training adaptations. Some movements & motor patterns are specifically counterproductive to achieving certain postures and positions.
All the stretching--cussing, pushing, prodding--in the world cannot undo these adaptations if you continue to train the movements that promote them.
Training & programming must promote positive tissue and nervous system adaptations if you want optimal health and performance.