The rectus abdominis muscle is located in the front of the body, beginning at the pubic bone and ending at the sternum. It is located inside the abdominals. The muscle is activated while doing crunches because it pulls the ribs and the pelvis in and curves the back. The muscles are also used when a child is delivered, during bowel movements, and coughing. Breathing in and holding the rectus abdominis in pulls in the abdomen. When this muscle is exercised and layers of fat disappear from the abdomen, the exposed rectus abdominis muscle creates the look of a six pack. Strengthening the muscle also improves performance in sports that require jumping. The rectus abdominis muscle leads to an area that comprises of the lateral abdominal wall. When doctors perform ultrasound-guided techniques on patients to locate the proper area for needle insertion, they sometimes start scanning at the rectus abdominis muscle to distinguish between the internal oblique, transverses abdominis, and the peritoneal cavity.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Rectus abdominis