Post by imperfectgolfer on Dec 8, 2023 10:32:59 GMT -5
Just thought I'd add this Phil Cheetham Sportsbox explanation of Chest Side Bend. I am really confused about this because I thought the AC joints can be moved independent of each other by the scapula, therefore how can this be associated with 'Chest Side Bend'? Also , other body movements could cause that 'line' connecting the AC joints to change its inclination with the horizontal plane (such as pelvic tilt).
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"There's been a lot of talk about chest (aka Ribcage or Thorax) side bend lately so I thought I would contribute to the discussion with some more info. This is a slide we use in our Sportsbox Level 1 Certification. Sportsbox also uses the AMM standard 3D model and algorithms.
Basically, if you draw a line between the two Acromioclavicular (AC) joints, side bend is the angle the line makes with the horizontal plane, and it follows you as you turn. The table is data from the AMM tour pro driver database and if you look at the graph you see that lead (left) side bend typically maxes out before top of backswing and maintains a similar angle until early downswing. Some golfers (like Rory) increase the lead (left) side bend a little more early in the downswing before rapidly progressing to trail (right) side bend at impact. Notice that side bend actually reaches max after impact. You can see this from the numbers in the table and the graph. Hope this helps."
"This is just one measurement and most measurements in the body are connected to what’s happening below. There are two specific measurements that AMM, Sportsbox and most golf 3D analysis systems make. They are segment angles and joint angles so if you want to see what’s contributing to the chest side bend, you can also look at the spine side bend, and the pelvis side bend. But that’s not to say that the chest side bend measurements don’t give significant information, they do.
The measurement in the slide is the side bend of the chest, but remember the chest sits on the pelvis so if the chest stayed stationary and the pelvis tipped and took it with it then yes, the pelvis affects the side bend number as well. If you want to just look at the side bend of the chest relative to the pelvis that is called spine bend. And there’s another set of data available for that.
Gears Sportsbox and AMM all measure side band as well as several other systems."
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DG
I can understand your concern about independent motions of the clavicle affecting the measurement of chest side-bend, but I suspect that the amount is very small in most pro golfers.
Jeff.