Your core - or, according to the discipline of pilates, your powerhouse - is the point from which all you movements originate. That's why it is vital to maintain a strong, healthy core that helps reduce lower back strain and chances of injury.
This video goes over the top three exercises you can use to prevent back injury, including crunches, Superman poses, and planks. You'll also learn how to rehabilitate your body after an injury.
Remember to work your core (crunches, planks, Supermans), stretch you hamstrings daily (helps lift properly), and lift properly (quad strength).