The most important exercise to implement to prevent low back pain. Where the exercise got its name I have no idea, but this is an excellent way to strengthen the posterior chain, which includes the glutes, hamstrings, and low back muscles.
To perform the exercise start with your feet shoulder width apart. Preferably, if you have never done this exercise before, stand with a dowel (broomstick) across your back. No dowel? Simply cross your arms over your chest. Stand 8-10 inches away from a wall.
To begin, collapse backward, breaking at the hips while bending the knees. KEEP THE SPINE NEUTRAL! Do not round the lower back or overextend the hips. Do not allow the mid back overextend. Also, keep the neck in line with the back. Do not look up or down during the movement. Simply allow the hips to move backward and allow the face to follow the movement. Lower until the hips hit the wall. Reverse the motion by contracting the glutes and moving the hips forward, away from the wall.
The most common mistake is to simply bend forward. If your hips do not touch the wall, you are doing it wrong! Think of the exercise as a front to back movement. It is NOT up and down. Remember, to ALWAYS use the glutes to push forward on the return movement.
Start with two to three sets of 15 reps once per day. This is not a time to show off to friends. You are using this as a rehab exercise and not a bodybuilding movement. Working up to using 10-20 pounds is usually enough. Rarely would a person need to go over 45 pounds, although athletes can moderate weight accordingly to help with speed?
If you have a disc issue (disc bulge, disc herniation, IDD, etc.), you may have to alter the range of motion to avoid putting too much stress on the problematic disc.
Now, of course, you always want to include core work as part of your routine to restore balance to the body. Planks are a great way to accomplish this when utilizing the Good Morning (SPOILER ALERT: Be on the lookout for an upcoming core exercise). This is not a guarantee that you will never have low back pain again, but it is your best chance to reduce the likely hood.