I'm sure you've been told that your depression, your fear, and your anxiety is all in your head. Actually, it may all be in your ass. That's thanks to the psoas major muscle, sometimes called the ...

For many runners, tight or achy hip flexors pop up at some point during training. But you shouldn’t just ignore them, as it’s often a sign your muscles need some TLC. Your iliopsoas is one of the ...

Tight hip flexors, especially a deep muscle called the psoas, can silently stress your spine. Here's why this muscle deserves more attention—and how to strengthen it. Lower back pain is often blamed ...