Which muscle is a stabilization muscle of the core?

• A. Diaphragm
• B. Psoas major
• C. External obliques
• D. Pelvic floor muscles

Answer: (A)

Stabilizing the spine during movement comes from a system that creates intra-abdominal pressure by coordinating breathing with the deep core muscles. The diaphragm is essential here because its contraction helps pressurize the abdomen and support the lumbar spine as you brace the core. This breathing-anchored stabilization keeps the spine in a safe, neutral position during lifting, bending, and twisting, making the diaphragm a key stabilization muscle of the core.

Psoas major is mainly a hip flexor, so its primary role isn’t core stabilization. External obliques assist with rotation and lateral movement, rather than providing static stability. Pelvic floor muscles do contribute to core stability, but the diaphragm’s role in generating intra-abdominal pressure through breathing is the defining reason it’s the best choice here.