There’s a big knob right at the bottom of your low back on either side of the spine. It’s called the posterior superior spine of the pelvis. Chiropractors call it the PSS. One PSS or the other is commonly the epicenter of a lot of low back pain—sometimes both. You can do every type of therapy on that area you can think of and nothing gets rid of the pain, because the problem isn’t there.
The sacro-iliac joint (SI joint) in the front of where your sacrum and pelvis articulate makes figure eight movements, with each side's figure eights moving in opposition to the other. Holding the SI joint together is a complex ligament called the iliolumbar ligament. The iliolumbar ligament keeps those figure eight movements in a nice tight orbit—not letting the joint do any weird movements. This area is your core.
When either one of these ligaments gets sprained (injured so it does not have as much strength/tonus), the pain is usually felt in the back on the opposite PSS. When most people get injured, the favor the injury by letting one foot toe out and shifting their weight to the other leg. Those type of accomodations cause the pain to switch sides. And no amount of work in the painful PSS area will resolve the pain, which can become intense and disabling. Often the pain is described as "burning pain." When I rub out the attachment site of the injured iliolumbar ligament, and realign the spine, the pain is often relieved in a single session, although it can require more treatments when the injury is extensive. The patient has to do their part in performing spinal corrective exercises multiple times daily (more often—and gentler—when the injury or instability is severe).
The patient does a “left knee lift” (in the northern hemisphere) where they keep their low back concave while they lift their left knee against resistance from their left hand on that knee. As you lift your left knee against resistance, it jacks the right side of the sacrum and pelvis back up into normal alignment and realigns the lateral deviation (scoliosis) out of the lumbar spine. This exercise also pulls the low back into its normal concave curvature The crucial part of this exercise is keeping the low back curve concave throughout the entire exercise. The left knee lift exercise is incredible. It works not only when your low back maximally injured, but also if you want to compete at the highest levels of physical activity. I do it a lot when skiing.
*It is important that you check with your chiropractor or physical therapist before starting this exercise in case there is a sprain that causes your low back to bow out to the right instead of the normal deviation to the left here in the Northern Hemisphere.
I also recommend doing gentle spinal twists, at least 15 times each direction, which breaks up the muscle tensions in the entire spine, and even into the hips and legs if you do them while standing with your feet parallel. You get much better reslults if you do the spinal twist while you are in good posture with your elbows out to the side. Each time you do the spinal twist, you eliminate a day’s worth of arthritic build-up out of your spine while also rehabilitating your inter-vertebral discs. The most important part of this exercise is to do it gently. This is especially important for all you overachievers.