The Transverse abdominis is an abdominal muscle deep in the lower belly that can save your lower back. A well-toned transverse abdominis in balance with the other abdominal muscles (internal and external oblique and rectus abdominis) goes a long way towards stabilizing the lower spine.
The transverse abdominis wraps around the trunk like a corset. It begins on the outside of the inguinal ligament, the inner lip of the iliac crest, the inside of the bottom six ribs, as well as the diaphragm and the thoracolumbar fascia. The transverse abdominis ends on the linea alba, the middle line of the abdomen. It is easy to think of it as one muscle but there is actually one on each side. While all of the abdominal muscles are distinct in and of themselves they are essentially connected through tendon and fascia, and need to be developed with an eye towards balanced tone in all of them.
The brain doesn’t simply know to use the transverse abdominis in a given exercise; it needs to be developed so that it is available for work when it is called upon. Unfortunately for our bodies the rectus abdominis, our sit-ups muscle, tends to answer the call when an action is required. You need to train your muscle/brain connection to recruit the correct muscle for the job.
This video is one of a three video training series that we released a month or two back on three muscles of back pain. This series focused on a number of muscles that, like the transverse abdominis, factors into a great deal of back pain issues.
We can’t truly isolate muscles– they tend to work in groups and chains, but when it comes to developing core tone I think it is important to try our best to engage and feel individual muscles. For example I love plank poses of all kinds but it is way too easy to use everything but your abs when doing them.