Originally Posted by Talvi
Exactly, it DOES force me to do that (but I always work to avoid pain - as per a yoga approach). And I could roll on the bed so no problems in doing that. However, what I see in the video is that his arm never moves out of the plane of his body so lying flat shouldn't be a problem.
Could you identify the moment in the video in the slo-mo section between 0:24 - 0:33 when you see it doing so?
Do you mean Shinji's video? Dave and Shinji are both freakishly flexible. But watch dave's video 1:31-1:38, his right arm (arm on the left side of the screen.
The elbow stays "high" in this video as in high close to the cieling, the upper arm is still at the same angle at 1:31 vs 1:38. But to drop the forearm and allow the shoulder joint to not be stressed he rotated his torso to do it.
The issue with being on the bed is that you'd have to rotate against gravit and it would just get messy. Doing it without rotating the torso, ie moving the arm instead doesn't mimic swimming action as well because it seems to encourage moving in an "S" shape.
So the "S" shape may happen, but watch Dave. From 1:31-1:38 his catch is set up and there is no scull and no stress on the shoulder, jus tthe timing of dropping the forearm with body rotation.