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 ...

A frequent source of lower-back pain comes from two muscles you might not have heard of—and that makes sense since you rarely see them on those medical posters of human anatomy in doctor's offices.

Sitting, standing, and moving between the two seem almost involuntary, but your body's muscles are working hard to make these motions happen. Your skeleton has over 600 muscles attached, and many of ...