"Tummy muscles" refers to the muscles in your abdomen or belly. These muscles help you maintain good posture, support your back, and play a role in various body movements like bending or twisting. Full definition
Do this at every diaper change and your baby will be rolling and sitting with strong tummy muscles in no time at all. (day2dayparenting.com)
the number of pregnancies — first pregnancies tend to be smaller bumps because tummy muscles are tighter (health-and-parenting.com)
We check for a diastus gap in your abdominals and work on pelvic floor recovery to get you back into shape, avoid leaking when exercising or sneezing / coughing, plus closing tummy muscles. (longibbons.com)