[header] How to strengthen your lower back [title] Make a hip bridge. [step] The hip bridge also works to strengthen the muscles in your lower back and core that support your spine, putting you at less risk for lower back pain. Lay on your back for this exercise with your knees bent and feet flat on the floor, as you did for pelvis tilts. 
[substeps] Lift your hips toward the ceiling, keeping your knees bent and engaging your core. Stop when your hips are even with your knees, such that you could draw a straight line (or a bridge) from your knees to your shoulders.