In those with back pain, however, the transversus abdominis didn't fire early.
From the nytimes.com
The transversus abdominis muscle is flat and triangular, with its fibers running horizontally.
From the en.wikipedia.org
The brain apparently alerted the muscle, the transversus abdominis, to brace the spine in advance of movement.
From the nytimes.com
The exercise focuses on regaining control of the trunk muscles, also known as the transversus abdominis and multifidus, which support and control the spine.
From the sciencedaily.com
To achieve perfect posture, you'll need to develop your transversus abdominis, which lies beneath your other abdominal muscles and runs horizontally around your abdomen.