Which muscle is a stabilization muscle of the core?

• A. External obliques
• B. Quadrates lumborum
• C. Pelvic floor muscles
• D. Transverse abdominis

Answer: (C)

Stability of the spine comes from the deep inner muscles of the core that brace and support the pelvis and lumbar region. The pelvic floor muscles form the base of that inner unit, helping to maintain intra-abdominal pressure and keep the spine aligned during movement. They coordinate with the diaphragm and other deep stabilizers to protect the spine in everyday activities and exercise, making them a fundamental core-stabilizing component.

External obliques are more about moving the trunk—twisting and bending to the side—rather than primarily stabilizing the spine. The quadratus lumborum supports the spine and helps with lateral stabilization, but its main role is not the foundational stabilization of the core. The transverse abdominis is also a key stabilizer, drawing the abdominal wall inward to brace the spine, but the pelvic floor is identified as a primary stabilizing muscle within many core-stability frameworks.