I followed this tutorial

https://vimeo.com/210956195 [vimeo.com]

Which overall I found to be very helpful.
However, when I created a test calisthenics animation, I discovered that the spine stretches when I animate the Spine_Chest_ctrl up in Y!
I would expect some kind of IK or other constraint, preventing the spine from stretching.
What am I missing?

thanks

That rig was designed to have a stretchy spine.

Ah! Ok. Good to know.
Thanks.
In that case, how would one go about modifying the rig so that the spine wasn't stretchy?
I don't want to have to manually maintain the “correct” length while animating my character.

I think Michael used an expression on the bone length to make them 1/6 the length of the spline used at all times (being that he used 6 bones I think). If you leave the bone length param at the default length as created (no expression), it won't stretch, however, the IK spline can still stretch pass the bones which may or may not be a visual bother.

yep - just remove that expression on the spine bones.

I'll give that a try.
Much thanks!

Removing the expressions from the spine bones fixed the stretching sping problem.
But the shoulders behave unnaturally.
i.e. the shoulders float above the head.
How do I prevent this from happening?
I guess I am expecting the spine, shoulders, neck, etc, to maintain a fixed length as well.
How would you rig the Spine_Chest_ctrl node to behave more like the way the hand and feet controllers work?
In what situations would you want the spine to be stretchy? Other than a cartoony squash/stretch effect?