As this asana’s name would indicate, the belly region of the body is the focus of this twist; therefore, many people assume that this twist arises from the lumbar spine. This is incorrect, however, because the lumbar spine is extremely limited in axial rotation (5 degrees total). The first joint above the sacrum that is capable of significant twisting is T11-T12, and that is where the opposition of the rib cage to the pelvis begins.

To ensure, that this twist is evenly distributed through the spine, it is important to maintain a neutral spine. This is a challenge with both knees bent because it’s much easier to move into lumbar flexion to keep the rotation. However, this puts pressure into the lumbar vertebrae and disks, as well as leading the T11-T12 disc. Another challenge to the neutral spine is that tightness in the lateral line will pull the spine into extension, lifting the far shoulder off the floor and compressing the brachial plexus. This often results in sensations of numbness or tingling in the arm.