The transversus abdominis is like a corset around your abdomen. It's
the muscle you work if you pull in your stomach.
Multifidus is a muscle that lies along your spine from your neck to
your pelvis, with short fibers connecting one bone (vertebra) of the spine to
other vertebrae near it.
The muscles of the pelvic floor are most noticeable when you squeeze
to keep yourself from urinating.
