What do the lower back muscles do?

The erector spinae are long muscles that run either side of the spine. They straighten the back and hold it upright, especially when you bend forward to lift something. They work with the glutes and hamstrings every time you hinge at the hips.

How do you train your lower back?

Controlled exercises like the bird dog and back extension train these muscles to hold the spine steady. Hip hinge movements, like the Romanian deadlift, train them together with the glutes and hamstrings. If you have back pain, see a doctor or physiotherapist before starting, as these pages are general guidance, not treatment.