[Flexibility Friday] The Thoracic Spine

Welcome to Flexibility Friday. The point of this thread is to discuss flexibility - techniques, tools, struggles, and hardships.

The current topic du jour: the thoracic spine or t-spine. It makes up most of your back, approximately from the bottom of your neck down to your belly button. Most people don't know if t-spine mobility is a problem for them, until them attempt things like back bridges, overhead squats, or handstands. T-spine extension is what allows you to "sit tall" in the bottom of a squat, and what allows a rounded back bridge instead of one with excessive lumbar bending.

So give us your t-spine mobility and flexibility tips.

(This is, of course, open to all questions regarding flexibility. Feel free to ask)