I've been reading up on stride length and velocity this week too, in attempt to help my son target the appropriate off season non-throwing training exercises. There is so much internet content on this subject, with many conflicting opinions that I feel the more I read the less I understand … and shit, I have college degrees in both physics and mechanical engineering. The aggregate search results on this subject are quite frustrating and I am about to give up on the cerebral pathway to pitching stride enlightenment.
How do you help a 13 yr old pitcher (who lacks the maturity to embrace PT exercises but understands why adults carry a pocket radar to tournaments) understand "loading the back hip/posterior chain and using that to create momentum down slope of mound"? … seems that the boy needs to learn to feel it in his physical manifestation, and I should not expect him to think his way into action.
Last off season, my son attended an NPA assessment weekend - the results indicated that his stride distance on flat ground was too short by ~16 inches (he was 6 ft tall at the time). I can't have him worrying about stride length while he is competing.
COACHLD - Are there one or two non-throwing exercises you can recommend that will lead to better mobility, stability and functional pitcher strength?