In my time working with a lot of people who have or have had low back pain, the psoas muscle has always been brought up as the cause of their pain. It has been blamed by everyone from previous trainers, to chiropractors, to massage therapists. On the surface, the reasoning for this is straightforward and formulaic. The psoas (or really the iliacus and psoas major muscles together) acts to provide hip flexion, and also originates from the spine. If someone has a “tight” and short psoas it would theoretically pull them into more anterior pelvic tilt and result in low back pain.
According to LMT’s, chiropractors, and trainers, the solution to this problem is to simply massage or stretch the psoas so that it is no longer tight. In reality it isn’t this easy. If it was, then a large portion of the population would no longer have low back pain.
The psoas lies deep within the body. It’s not easy to palpate and find like your quad or bicep would be. Even a therapist who knows exactly where the psoas is likely won’t be able to effectively get to it as it lies behind a wall of abs and guts. But the psoas is so hard to get to, and it hurts so much, that getting work on it must be doing something good, right?
In reality, no one has the slightest clue if the psoas is the cause of low back pain or anything else really. It’s just another muscle that acts on the spine, nothing more. Sometimes I’ve even heard that the psoas itself has to be strengthened because it helps to stabilize the core. In this case it is actually even less important than other muscles such as the quadratus lumborum which has been shown to be a better stabilizer of the spine than the psoas (Mcgill, 1996).
So what’s the solution for your low back pain? The psoas is “pso” overrated; because the answer can be anything. Low back pain is so multifactorial, and pain is so multifaceted, that any number of solutions can help you get out of pain, or make it worse. Whether it’s a purely biomechanical, neurological, or psychological issue, it can’t be determined. It’s most likely a combination of all of these, and without a proper assessment from a knowledgeable professional, there’s no way that you will know either.