One of the most important things you can do for your lower back is keep your core strong and integrated with your spine. I'll explain. Have you ever seen a large sailboat? Picture the mast on the boat. What is attached to it? Riggings. Lots and lots of riggings. If those riggings are not there, the mast on the boat falls over. The mast can't support its own weight without all those lines attached to it. Your spine is similar. The human spine, on its own, without anything attached to it, can support about 35 pounds of weight. No matter how thin you are or are not, you weigh more than 35 pounds. So your spine relies on all the muscles, tendons, and ligaments attaching to it in order to support it. Without these attachments, your spine would break!
When the muscles attaching to the spine are tight, weak, or improperly balanced, the spine experiences torques in suboptimal ways and increased pressures are placed on the intervertebral discs and small facet joints in the spine as well as other spinal structures. Over time, these increased pressures can lead to disc tears, arthritis, and back pain. By stretching and strengthening the muscles around the spine, you unload the spine and take the pressure off of these potentially painful structures.
Now a note on strengthening: When I take care of professional athletes, and I tell them we need to get them into physical therapy to work on "core strengthening," they often look at me initially like I have two heads. After all, these men and women often have 6-pack abs and they work out everyday! That's when I explain to them that it's not just about "strengthening." Physical therapy is also about integrating the core muscles in ways that protect the spine.
Certain exercises are better than others at teaching the muscles how to contract in order to protect the spine. Ultimately, what we are after is for the muscles to contract effortlessly all day in ways that continually protect the spine from experiencing increased torque and pressure. For example, when you do something as simple as opening a door, your abdominal muscles need to contract properly in order to protect the spine! When a professional athlete comes back after four weeks of physical therapy and his or her pain is 80% improved, I know we've successfully targeted and taught the muscles to protect the spine. In another four weeks, the pain will likely be all gone. Either your doctor or a physical therapist (ask your physician for recommendations) can teach you exercises you can do at home for your specific back pain.
Once spine or back pain is gone after physical therapy, it is important to continue doing a home exercise program on a daily basis. This will keep the muscles flexible, strong, and functioning properly so that hopefully the pain does not recur. Ideally, we would all do the exercises everyday before any pain ever occurred. After all, since at least 80% of people experience back pain at some point in their life, we could all use some exercises to keep our core strong, flexible, and integrated. In reality, many people don't do their exercises until they develop pain.