MRI shows selective psoas and rectus atrophy with reduced trunk strength in chronic low back pain, suggesting functional imbalance.

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.

If you have chronic lower back pain—meaning a nagging ache has persisted for 12 weeks or more—you may be tempted to throw a bunch of Dr. Google remedies into a bag, shake it up, and start drawing at ...