The abdominal muscles are a group of muscles that run from the chest to the pelvis. They are responsible for the movement of the trunk and spine, and also work to stabilize the pelvis and lower back. The abdominal muscles are made up of four main muscle groups: the rectus abdominis, external obliques, internal obliques, and transverse abdominis.
The rectus abdominis is a long, flat muscle that runs down the center of the abdomen. It is responsible for flexing the spine, as well as helping to support the organs in the abdominal cavity. The external obliques are located on either side of the rectus abdominis, and they help to rotate and flex the trunk. The internal obliques are located underneath the external obliques, and they work to stabilize the pelvis and lower back.