GEARS Pro Data: Elbow Bend vs. Lead Arm Adduction

[iacas]

I have 61 swings (29 drivers, 32 irons (two of which are wedges) with full club and body data of men and women Tour players (or former Tour players) in my GEARS system. I've put some of the data from all of them in a spreadsheet and with that, I can plot a number of things against each other. I'm open to soliciting and creating charts that show you any of the data.

In each of these topics, I'll present the data in a chart of some kind and share the data in the quartiles (min, 25th, average, 75th, max) as well as the standard deviation.

Here's the chart for a selection of the players in the database with irons and driver:

 

GEARS measures the lead arm adduction as the angle at the lead shoulder joint to the next segment out in each direction: the lead elbow and the spine. Shoulder retraction and protraction as well as of course the internal and external movement of the upper arm can affect this number.

GEARS measures the elbow bend as the bend of the trail elbow joint, with 0° being a straight or fully extended trail elbow and 90° being an elbow that's bent 90°. You cannot achieve 180° of bend, as the angle is the BEND angle, not the absolute angle. So an arm that is bent 110° will be bent 30° more than an elbow that's bent 80°.

The charts below show the independent min, max, quartiles, etc. at each position.

Irons

            Elbow Bend     Adduction
Low            55.49         42.37
25th           77.60         56.62
Avg.           90.93         61.90
75th          104.24         68.49
High          121.75         80.21
Range          66.26         37.84
Std.Dev.       17.60          9.04

Drivers

            Elbow Bend     Adduction
Low            65.13         40.35
25th           83.63         51.36
Avg.           98.58         57.87
75th          113.43         65.77
High          125.24         74.08
Range          60.11         33.73
Std.Dev.       16.44          8.79

If you'd like to request some processed GEARS data, please send me a DM.

[Ty_Webb]

Curious what your thoughts are on this @iacas - the impression I get is that the range of both factors is very high - so high as to suggest that there is no "right" place for your arms to be in at this stage (A4 is top of backswing?). Right arm can range from 60 to 110* of bend and left arm (rightie golfer) can be anywhere from 40* to 80* adducted (I think this means across the chest). I guess I'm not sure if 90 means straight out or tight across the chest. I would think straight out because 80* would be so far across the chest as to be unworkable otherwise. Only real meaningful thing from it is the more bent your right arm is, the further across your chest your left arm has to be. It seems anatomically it would be difficult to have much otherwise unless your left arm is also bent at the elbow.

[iacas]

Both of the numbers are explained in the post, @Ty_Webb.

29 minutes ago, iacas said:

GEARS measures the lead arm adduction as the angle at the lead shoulder joint to the next segment out in each direction: the lead elbow and the spine. Shoulder retraction and protraction as well as of course the internal and external movement of the upper arm can affect this number.

GEARS measures the elbow bend as the bend of the trail elbow joint, with 0° being a straight or fully extended trail elbow and 90° being an elbow that's bent 90°. You cannot achieve 180° of bend, as the angle is the BEND angle, not the absolute angle. So an arm that is bent 110° will be bent 30° more than an elbow that's bent 80°.

And I think you'll notice that not many are below 50° or 55° adduction, with those also tending to be the higher elbow bend players.

Trail elbow height would influence the elbow bend vs. adduction stuff, too.

[boogielicious]

How do these numbers relate to the depth/height of the backswing at A4? For example, if my swing got too flat, would the adduction be a smaller and and the elbow bend less? The chart trend seems to suggest adduction and elbow bend go that way.

[iacas]

1 hour ago, boogielicious said:

How do these numbers relate to the depth/height of the backswing at A4?

They… don't?

I think you understand what these measurements represent, so if you picture bending your right elbow 90°, I think you can picture how you can still move that in space in two directions:

• Up and down (vertically).
• Around beside you or more in front of you.

The latter would affect the adduction and the depth, the former wouldn't do much to affect the adduction.

The adduction is just basically how large the angle between your lead pec and lead upper arm is. So you can move your left (lead) arm up and down and not affect the depth or the adduction much.

1 hour ago, boogielicious said:

For example, if my swing got too flat

We're talking about your left arm being lower (= "flatter") from the DL view here? I'll assume that in answering…

1 hour ago, boogielicious said:

For example, if my swing got too flat, would the adduction be a smaller and and the elbow bend less?

The adduction angle is the actual angle, so the closer your left arm is to your chest, the smaller the angle and the "more adduction" you've done.

Basically, your left arm hanging straight down is 90° adduction. Lift it up horizontal, still 90°. Move it 45° to the right, and it's 45°. So keeping your right elbow down at your side and bending it a bunch tends to pull the left arm across your chest.

Interesting thing though: if you bend your left elbow too, your adduction angle can stay wide even though your hands get pulled around, because the adduction angle is just measured to the elbow. Elbow to shoulder to spine, that's the angle.

1 hour ago, boogielicious said:

The chart trend seems to suggest adduction and elbow bend go that way.

More elbow bend tends to lead to more adduction.

[boogielicious]

Got it thanks. I’m working to understand all the data terms so it will be easier when I come for my session.

[iacas]

35 minutes ago, boogielicious said:

Got it thanks. I’m working to understand all the data terms so it will be easier when I come for my session.

The visuals help.