there are a few things you can do to help strengthen your lower back.
1. Flexibility exercises that target your hamstrings and hip flexors.
2. Abdominal strength training.
3. Isometric back extensions.
4. Back extensions on a back extension machine.
5. R/elbow to left knee, L/elbow to right knee in a smooth twisting motion.
If you have any trouble with your back I would suggest that you see your doctor before starting a back program.
Alan