One of the most common causes of elbow pain in pitchers - and even some folks in the regular population - is a loss of elbow extension range-of-motion over time. With pitching, there is extremely high-velocity elbow extension that must be decelerated (eccentric action) by all the elbow flexors (biceps, brachialis, etc).
Because eccentrics are the most damaging types of muscle actions, the muscle can shorten over time, leaving the elbow in a flexed position. Research has shown that the muscles shorten acutely (after a pitching bout) - and it isn’t a stretch to assume (particularly based on my anecdotal experience from the pitchers I’ve seen) that if these ROM deficits aren’t addressed right away, they’ll become chronic (over the course of a competitive season).
For this reason, we encourage all our pitchers to work hard at regaining elbow extension ROM immediately after a start with this stretch.
When we get a guy who comes to use with chronically restricted elbow extension ROM, soft tissue work - be it general massage, Graston techniques, and/or ART - are important immediate inclusions. As the picture below shows, they can leave some marks, at times, but in this guy’s case, just five minutes of soft tissue work and the above stretch got him over 10 degrees of ROM back. He probably won’t get all his ROM back, but he’ll certainly get a lot closer to it.