The abdominal muscles of the external abdominal obliques, internal abdominal obliques, rectus abdominis and the transversus abdominis form the anterior and lateral abdominal wall. Working together these muscles form a firm wall that protects the viscera and they support to maintain the erect posture.
In addition, the contraction of these muscles assists in expiration and to increase the intra-abdominal pressure such as in coughing, sneezing, micturating, defecating, lifting and also childbirth.
