A long flat muscle that extends along the whole length of both sides of the abdomen. It flexes the vertebral column, particularly the lumbar portion; it also tenses the anterior abdominal wall and assists in compressing the abdominal contents. It is frequently the site of hematomas. In PLASTIC SURGERY PROCEDURES it is often used for the creation of MYOCUTANEOUS FLAP. (From Gray's Anatomy, 30th American ed, p491)

(rectus abdominis muscle) Two vertically parallel muscles located on the anterior abdominal wall, which originate on the pubic crest and insert on the coastal cartilages of ribs five through seven and the xyphoid process; both muscles function to flex the lumbar spine.