[coophitter]

Most folks see movements of the whole spine differently or similarly depending on what it is that they agree upon to see. There are three academically agreed upon sections of the spine that can manoeuver independently from each other or in concert with each other. If any or all of these sections pivot from a starting condition then there can be no sway (or bob). Each section can likewise sidebend, flex, or extend in concert or independently. The lumbar joints are typically less flexible and offer less range of motion than the thoracic joints, and thoracics likewise are less flexible and mobile compared to cervicals. Things get mighty complicated when the three sections are connected and thereby influenced by movements of scapulas, shoulders with humeral heads, pelvises with femoral heads, etc.

Regardless of the inherent complexity of observed spinal movements, if any section of the spine pivots from an original vertical, sidebent, flexed, or extended condition, then that section will retain its original condition. Otherwise the section or sections in question did not pivot. Most golfers start with a bit of sidebend away from the target with all three sections of the spine. If they truly pivot then the original sidebends are retained.

Perhaps "pivot" needs to be redefined for golf swing observations and resultant commentary. Perhaps golf swing observations and commentary concerning pivots are intrinsically too difficult for the human eye to accurately perceive because in the pivoting of any object with girth, the frontal view of a point on that object will move in the opposite direction of a point 180 degrees away on the backside of the same pivoting object.

If all agree that any segment of the spine is tilted or sidebent away from the target at address then all must agree that that segment will remain in that tilt or sidebend if it truly pivots thereafter, even though it may not look like it is truly pivoting from a different point of view. Otherwise we need to call segmental movements of the spine during the golfswing something else as we tend to do when we observe that at least a portion of the spine sidebends a bit more away from the target(secondary axis tilt) to facilitate a good downswing.

By the way, I'm probably like most experienced video teaching pros in that I have never witnessed what I could honestly diagnose as a pure backswing or downswing pivoting of the segments of a given spine in any given swing I have ever analyzed.