The shoulder rotation thing is interesting. Having recently posted in the
Video Serve Analysis thread, where there was a conversation about shoulder rotation (vertical versus horizontal axis) along with body rotation - specifically
over rotation - this is something I'm trying to understand more. Imo it is obviously quite a common problem among amateurs, and something I can actually feel myself doing from time to time. I've been working on not tossing into the court as much since that is a definite trigger for me; other than trying to stay a little more sideways early in the racquet drop stage, I haven't focused on anything else. That's because, once we've seen a live demonstration of what we want to achieve, I firmly believe we have to find ways of tricking the body with cues or thoughts that the brain already understands, and so they can't be bio-mechanical in nature.
I posted images of Serena Williams in another thread about camera angles and judging low elbows at trophy (added again down below).Then seeing another image of her posted by
@ballmachineguy, I went out yesterday and hit a few from a similar angle (not quite exact, but very close).
Full size image can be
downloaded here.
@Curious, does that not look like shoulder over shoulder to you?
I think frame 2 is called maximum ESR and frames 4 through 7 are ISR (although I always thought it was a combination of pronation and ISR, and that's why Chas looked for shadows on the elbow and upper arm, which obviously aren't present here). I shouldn't have worn the hoody, but it was windy and cold.
Roddick for comparison versus frames 5 and 6 (frame 6 is just past contact for me but the video was 60fps and is the closest match)
Serena versus frame 2:
As a reminder of what camera angles can do, Serena's elbow (which isn't low).
I used to be worried about that, but I now think I'm well within the 20° range of acceptability that Brian Gordon prescribes (rear views of my serve from other videos are contributing factors to that belief).
No to both. But they don't need to do they? Coaches and bio-mechanical scientists can study that stuff using high speed video and find out precisely what is going on. Then they can find ways to help make those things happen in a live environment by attempting to identify drills that work over time (initially there will be trial and error). Which is what I believe Brian Gordon does, as you state above.
Interesting point, and I've never heard you state it that directly before (not saying you haven't, just that I haven't seen it)! Based on your Karlovic statement above, does that mean in my montage I am using ISR to reach frame 7?
Final question for the gurus - do I still need to worry about over rotation, and if so, any advice on drills to help?