Does the Spine Angle stay the same throughout the entire motion of a Full Stroke ?

[Bagger Lance]

What in the world just happened. . .

Another LBG first.

I'm not going to "touch" this one.
Seriously though, the plane descriptions are helpful. I think.

Bagger

[yippedagain]

The 4 sections change. Something to do with Pitch, Yaw and Roll, if I remember one of Annikans earlier posts correctly.
The spinal column is rotating in a diagonal or oblique plane which is a combination of those great pics!.

[yippedagain]

Correction.- Axis of a diagonal or oblique plane.

[Martee]

My vote is for #4.

I think from down the line view many like to draw a straight line to represent the spine and its angle. And I think, no real knowledge that although that is nice and maintaining the angle from down the line seems to make sense to me, the spine is not a straight line and in order to accomodate rotation and shifting, parts must be in motion.