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 ...

4 Centre for Magnetic Resonance, University of Queensland, Brisbane, Queensland, Australia 5 School of IT and Electrical Engineering, University of Queensland, Brisbane, Queensland, Australia ...

When elite ultrarunner Mike Wolfe laced up for a tempo run in June 2009, his right hip flexor felt tender and sore. But nothing out of the ordinary for a runner who, in a weekend, can cover 75 miles ...

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 ...