The body is an interconnected system of moving parts governed by the laws of physics in the greater world around it. Dysfunction in one part of the body may tax other parts of the system, while healthy function in one area can upgrade and contribute to health in other areas,
I see this in the natural curves of the spine and how they are expressed in yoga poses.
I recently wrote about the lower back, and the most commonly herniated discs of the spine, at the very base of the low back (L4-L5 and L5-S1). In today’s article, I’ll zoom out from that area, looking at how a healthy mid-back (optimal curve in the thoracic spine) supports optimal function of the lower back and pelvis in yoga.
First, let’s look at the structure of the spine. The spine has natural curves, which are divided into three sections. Both the lower back and neck have a lordotic curve, meaning a curve that moves into the body, while the natural curve of the mid back (thoracic spine) is kyphotic, meaning a convex curve that rounds out.
A diminished thoracic curve, or flattened mid-back, is likely to affect other areas of the body, and specifically the mobility of the rest of the spine. When the thoracic curve is flattened, I’ll often observe that in the front body, there is a corresponding lift of the base of the sternum, along with a jutting out of the front, bottom ribs.
I’ve been interested lately in how this pattern in the mid back manifests in forward bends (and especially seated forward folds) in yoga. First, consider the two safe stages of completion in forward bends in yoga:
- STAGE 1: The pelvis must be able to tip upright to a neutral position, with the sacrum drawing IN and UP. If the seated pose begins in a posterior pelvic tilt, the top of the sacrum tips away from the body, the lumbar vertebrae in the low back round OUT and the discs of the lower back can be at risk. (Read more about the low back in forward folds here)
- STAGE 2: The spine folds forward, ideally with an even rate of forward flexion among the vertebrae. It’s this second stage that I commonly see affected by the thoracic spine. The mid and upper back often move forward more freely than the low back, and many times that movement creates stuckness in the low back.
Since many students have learned that a seated forward bend must first begin in the level pelvis described in stage 1, yogis commonly move deeper in a forward bend by tipping the pelvis anteriorly (forward), reaching their navel towards the floor. This action initially works to bring the pelvis upright, but watch in this video how it can be incomplete and contribute to the low back getting stuck.