GEARS: What do the Arms do in the Golf Swing?

[iacas]

Not much!

In the latest version of the GEARS software, you can draw an "axis" (a trim-colored graphic that points in the X, Y, and Z direction) relative to every body segment.

In the images below, I've matched up the torso so that the camera is viewing the torso from the same angle and I've taken a photo of the arms from both angles - setup and the top of the backswing - to illustrate what the arms do (relative to the torso/chest) during the backswing.

This is it. This is all the arms do in the backswing:

That's it. They:

• Lift (at the shoulders).
• Bend (the right elbow, often ideally < 90°).
• Hinge (at the wrists).
• Roll (slightly, or the club would be across the line at the top).

It's not much.

P.S. That's a four-time major winner right there.

[Darkfrog]

51 minutes ago, iacas said:

< 90°

Is this supposed to say >, or am I misinterpreting the information. I used to have a training device that essentially stopped the bend at 90 degrees, so the angle could not get smaller, and I thought this was a good thing to do (not collapse right arm bend).

[iacas]

19 minutes ago, Darkfrog said:

Is this supposed to say >, or am I misinterpreting the information. I used to have a training device that essentially stopped the bend at 90 degrees, so the angle could not get smaller, and I thought this was a good thing to do (not collapse right arm bend).

You're misinterpreting.

I said "bend < 90°." As in if you have a straight-ish elbow and you "bend" it 45°, it's "bent" 45°.

The actual angle would be 135°, but it's "bent" 45°.

[boogielicious]

Dude’s got four arms!

You posted a video a while back showing this too. Thanks.

[Darkfrog]

11 hours ago, iacas said:

As in if you have a straight-ish elbow and you "bend" it 45°, it's "bent" 45°.

Makes sense now, start at 180, don't bend past 90, not the angle of the right arm bend at completion of backswing. Thanks for clarifying.

[nevets88]

Now do one with someone sitting in the spinning office chair, lol.

So the arms don't do as much you'd guess but they do contribute a lot to club head speed, see the swings from off the knees? It's just that that speed/power is concentrated in those few moves? I remember something here about how the arms contribute to power more than you'd think, when ground reaction forces got a lot of attention. That's why I mentioned the office chair, there was a video of David Wedzik or someone taking a swing sitting in a chair getting a good amount of distance just from the arms.

[iacas]

5 hours ago, nevets88 said:

So the arms don't as much you'd guess but they do contribute a lot to club head speed, see the swings from off the knees? It's just that that speed/power is concentrated in those few moves? I remember something here about how the arms contribute to power more than you'd think, when ground reaction forces got a lot of attention. That's why I mentioned the office chair, there was a video of David Wedzik or someone taking a swing sitting in a chair getting a good amount of distance just from the arms.

Yeah, I've been thinking of how to kind of reconcile the stuff. For now, I'll say this:

• You can't make a very good swing with the right elbow staying straight, the wrists not doing much, etc.
• You can't make a very good swing ONLY by using your arms (though you can make a fast one).
• The arms don't do "much" but they work up and down FAST. This is a "multiplier" to the rotation, of sorts.

The video with the chair was mainly about GRF, not about how you "should" swing your arms. (Much too much "around" in those swings.)

[iacas]

[mdl]

Huge unlock for me around this was this AMG video. Short version is your only joint/bone connection between your arms and the rest of your body is the sternoclavicular (SC) joint where the collar bones attach to the sternum (green bit in the pic). At setup you've got ~90˚ between your arm and collar bone. Good players don't change that early in the swing. You can get past A2 without changing it at all by hinging the SC joint (push your shoulder forward and slide your shoulder blade away from the spine). This is what allows you to get good rotation while keeping the trail arm <90˚ bent, with the pro in the video only getting to 70˚. For me this was a revelation. So much less movement to time!

 

 

[iacas]

Is that the video you meant to link to? It doesn't have any angular measurements like the adduction angle, etc. It just talks about how the left shoulder works, not the arms, really.

[mdl]

18 hours ago, iacas said:

Is that the video you meant to link to? It doesn't have any angular measurements like the adduction angle, etc. It just talks about how the left shoulder works, not the arms, really.

Whoops. Yeah posted the wrong one.

 

[iacas]

I thought you might be referencing…

This image says it: