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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.  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. Hold the position for 5 to 10 seconds, breathing deeply, then lower to the ground. Perform 10 repetitions of this exercise. For this exercise, also known as the Superman exercise, you want to lay face-down on the floor with your legs extended behind you and your arms extended straight overhead.  If you're already laying on your back, flip over onto your stomach. Reach your hands over your head and extend your legs behind you. Raise your legs a few inches and kick them, alternating sides. You also can lift your left leg and right arm together, then lower and lift your right leg and left arm. Complete 10 to 20 repetitions of this exercise. The pelvis tilt helps strengthen the muscles at the base of your abdomen as well as the muscles around your lower back. Become familiar with contracting this muscle to help strengthen it so you have fewer lower back problems.  Press the curve of your lower back into the floor and hold it for 5 to 10 seconds, breathing deeply, then release. Do 10 repetitions of this exercise. To do this exercise, lay on your back with your knees bent so that your feet are flat on the floor. Your legs should be about hip-width apart. The bird dog exercise can help stretch and strengthen your lower back, as well as improving your balance. Start the bird dog exercise by getting on all fours with your knees directly under your hips and your wrists directly under your shoulders.  Reach your left arm forward and your right leg backward, creating a straight line from your fingertips to your heel. Keep your back flat, hold for two or three seconds, then return to all fours and repeat with the other side. Do 10 to 20 repetitions of this exercise on each side. Keep your back flat and motionless, and don't lift your hand or heel higher than your back. Lunges, if done correctly, are a good exercise to strengthen your lower back. Start by standing with your legs about hip-width apart. Make sure there are several feet of space in front of you.  Step forward with your right leg, lowering and bending your left knee. There should be a straight line from the top of your head to your left knee – don't lean forward over your right leg. Bend your right knee to a right angle with your knee directly over your ankle and your thigh parallel to the floor. Hold the lunge for a couple seconds, then step back to your original position and repeat with the left leg forward. Do 5 to 10 repetitions on each side. Since the muscles in your lower back are part of your core abdominal muscles, you can't strengthen your lower back without strengthening your core.  Start on your stomach with your legs extended behind you. Raise up so that you are on your hands and toes, with your body creating a straight line from the crown of your head to your heels. If you don't have much experience with planks, you can modify the exercise by coming to your knees and elbows, or to your toes and elbows so that your upper body is supported by your forearms rather than just your wrists. Side planks work the core muscles along your sides. Come up on one forearm, stacking your ankles one over top of the other. Make sure your elbow is directly under your shoulder. Once you've done these back-strengthening exercises for a while, they'll become less challenging. A stability ball adds a balance element to push your muscles to work harder. For example, if you put your feet on a stability ball to do a bridge, you'll find the bridge is much more difficult to do as well as to maintain.

Summary:
Make a hip bridge. Swim on the floor. Tilt your pelvis. Try the bird dog exercise. Add in some lunges. Engage your core with planks. Use a stability ball to increase difficulty.