Try this workout to for your lower back. Perform each exercise 15 reps for three sets resting only 25 seconds.
1. Back Extensions
Lock feet in, with pad comfortably on hips. Cross arms over chest. If using weight, hold weight plate at chest level. Pressing hips into the pad, relax the spine. Squeeze together (retract) shoulder blades. In a controlled motion, lift head and shoulders up until spine is comfortably hyperextended. Avoid hyperextending the neck. Maintaining controlled motion, return to starting position. Do not allow muscles to relax before next repetition.
2. Barbell deadlifts
With the loaded bar on the floor, stand close to the bar with your feet a little narrower than shoulder width apart. Bend at the knees and grip the bar about shoulder width with one palm facing in and one palm facing out. Get into a squat position. Keep your head up and the bar close to your shins. Drive through with your legs as you lift the weight up until you are standing in an upright position with your back locked. Keep the bar close to your body and squat back down, lowering the weight to the starting position. Do not allow muscles to relax before next repetition.
3. Ball Lower-Back Strengthener
Primary Muscle Group: Low back
Muscle groups worked in this exercise: Gluteus Maximus, Semitendinosus, Semimembranosus, Quadratus Lumborum, Iliocostalis Lumborum.
Preparation: Kneel on the floor and bring the ball up close to you. Lie forward on the ball with your abdomen right on top of the ball and place both hands on the floor in front of you. Extend your legs behind you and balance upon the balls of your feet.
Execution: Lift your left leg as high as you can while exhaling. As you lower your leg, inhale. Then repeat with the other leg. It's important to keep your torso stable and prevent wobbling. Alternate legs after completing all repetitions.
Comments: You'll notice that the ball will try to shift as you lift and lower your legs - this forces your abdominal muscles to stabilize your torso. Remember to pull your navel in and up towards your spine.