What Is the Psoas Muscle? The psoas (pronounced so-ezz) muscles are two large muscles in your lower back. You have one on either side of your spine. They're the main muscular connection between your ...

What is a psoas and how do I know if I have one? If your upper body attaches to your lower body, chances are good you have at least two psoas muscles -- one psoas major muscle linking your spine to ...

The iliopsoas muscle is the major flexor of the hip joint, made up of the iliacus and psoas major muscles. Pain in the iliopsoas muscle can be caused by sitting too long, muscle imbalance, overuse, or ...