If you’ve ever had that nagging ache in your lower back that just won’t budge—especially on one side—there’s a good chance a small but mighty muscle called the quadratus lumborum (QL) is involved. It ...

If you practice yoga, run, hike, ski, cycle, surf, swim, or just want to feel more stable as you go about your everyday life, you need to be aware of an easily overlooked pair of muscles that plays a ...