Which is the action of the transverse abdominis?

• A. Compress abdominal contents
• B. Flex the vertebral column
• C. Rotate head and neck to the same side
• D. Elevate ribs

Answer: (A)

Transverse abdominis acts to compress the abdominal contents, tightening like a corset around the abdomen. This action increases intra-abdominal pressure and helps stabilize the spine and pelvis during movements, especially when lifting or supporting the trunk. It doesn’t bend the spine, so it isn’t the muscle that flexes the vertebral column. It also doesn’t rotate the head and neck or lift the ribs—those functions are handled by neck muscles and the muscles involved in breathing and rib elevation, respectively.