Probably not typical but my son went to a PT who was very baseball savvy after he was diagnosed with GIRD, which I believe is due to tightness in the posterior capsule, while rehabbing from a stress reaction in his elbow. She stretched him out pretty good and gave him stretches to do every day. It was interesting to watch a PT who was more interested in helping than in adding on stuff they could bill for.
Within a few days he had picked up about 5 or 6 mph on his fastball.