FiveFrameSwing
Banned
Until a few months ago, I had no clue about the forearm brushing the hip. I think it was a conversation bewteen Bill Hillhouse and Rich Balswick that got me thinking about it, then Rick stopped by and gave it a name. I was skeptical, however, started looking at video and pics of high level pitchers and realized it's been right there all the time.
I think if you start with good posture and elbow leading to the side, forearm brush will likely happen. The key word is "brush." If you're getting "bump" and some discomfort, check the posture. I'm not sure it's super critical to force brushing vs setting up the conditions that result in it. That's something Rick or Rich might better address.
The concept has been around for over a decade. Doug Gillis referred to it as "brush assisted whip" in his old VHS pitching videos.
Rick is showing recent data he's collected in which the arm accelerates from 9-oclock to 6-oclock ... but it isn't just 'acceleration' that is important, but also 'deceleration'.