The oblique muscles are often thought of as the waist muscles. They contribute to pain on your side in the rib cage and waist area, lower abdomen, groin, and pelvis. They can also contribute to heartburn, indigestion, bladder pain and incontinence, and testicle pain.
The gluteus medius is located in the hip and buttocks. It can contribute to pain in the low back, hip, buttock, and down the outside of the upper leg.
The rectus abdominis contributes to pain in the area around the sternum, across the upper back, across the buttocks, the lower abdomen, the pelvis. and testicles. It can also contribute to heartburn, indigestion, feeling bloated as well as mimicking urinary tract infection pain.
The diaphragm is a muscle found under the lower ribs. It can contribute to breathing problems, pain in the chest, ribs, and can cause sharp pain in the side known as side stitches.