This exercise is one of the Core Four exercises that I assign at the outset of my CoreWalking Program. The transverse abdominis muscle is a deep abdominal muscle that helps to stabilize the spine in this essential exercise. The spine is a magical piece of equipment usually made up of 26 bones with four curves.
The psoas major is the muscle that holds us up, walks us through life; and warehouses our trauma and unprocessed energy (pretty big stuff). They all interact in the exercise feet three inches off the floor. As a collection of bones the spine is highly mobile. It bends, twists, extends and flexes. But it also solidifies. This dynamic of supple and solid is at the root of what I am trying to teach in my yoga classes.
Ideally the spine should be highly mobile at times—such as cat and cow—and a rigid pole at other times—such as plank. There are different issues when it comes to the mobility of the spine, or the lack thereof. Some people are too loose in both the ligaments and muscles, while some are too tight. An immobile spine is not easy to figure out.
As loose as I am in most of my joints, before I did an extensive course of treatment with a chiropractor about seven or eight years ago, my lumbar spine (lower back) did not move. And it took about six months of regular treatments before it gained the fluidity it has maintained ever since.
When working on the exercise Feet Three Inches Off The Floor, the psoas major does the work to lift the feet up. I always start with one foot at a time to be nice to the psoas, hip flexors and pelvis. This lifting of the foot by the psoas major is one of its essential functions but not the point of the pose.
This pose is meant to explore and develop the tone in the transverse abdominis muscle. If the tone of the transverse abdominis muscle is good the spine assumes it rigid shape and there is no change in the trunk when one or both feet come up off the floor.
Very often another muscle the rectus abdominis, our sit ups muscle wants to get involved but it has no role to play here. The rectus abdominis draws the pelvis and ribcage closer to one another, but that is not the action in feet three inches off the floor. The trunk wants to be stable, the spine rigid and the transverse abdominis muscle should provide that stability.
Not to be too dramatic but developing tone in the transverse abdominis muscle to accomplish this goal can go a long way towards alleviating back pain in many individuals.