I am examining ways to gain greater power from trunk/shoulder rotation and trunk flexion. The problem with the latter is that maximum angular velocity occurs late in the pitch, often post-release, and the best way to transfer greater power to the arm is to hyperextend the trunk and shift the timing away from release. The effect of this, however, is limited in that the average rate of flexion is only about one third of that of trunk/shoulder rotation. It seems that trunk/shoulder rotation offers greater potential for more power transfer if the maximum angular velocity coincides with max external rotation (full cocking) of the arm. Does data exist to show when max trunk/shoulder rotation velocity occurs in the pitch sequence? My sense is that it is well before MER. If it is indeed before MER, does the angular velocity decrease or remain relatively constant until MER?
If you want to speed up the trunk you must speed up the initial movement. Focus on increasing tempo and forward momentum since pitching velocity is mainly from linear...not rotational forces. Focus on a long stride and bracing action of the front leg and hip while getting the arm involved late. Most of a pitcher's velocity is already established at foot plant through stored elastic energy. However, there is a big opportunity to use those linear forces to engage the trunk's large mass and use it to gain that extra velocity after foot plant. I am sure Glenn can provide the studies to answer your other questions. Dick Mills www.pitching.com