There is one hip flexor muscle that often contributes to lower back pain: the psoas.
The psoas muscle is hard to find and easy to annoy. It is not just a hip flexor, it is also a spinal muscle and the only muscle to bridge the upper and lower body. You can learn more about the location of the psoas and how it relates to the other muscles of the torso by checking out these posts on core anatomy and hip anatomy.
How the Psoas Hip Flexor Causes Lower Back Pain
Because of its attachment points all along the inside of the lumbar spine, when the psoas muscle isn’t properly supported, strengthened, and lengthened it can pull on the vertebrae of the lower back. If this goes on long enough it creates conditions that are conducive to spasms. When you hear someone say that their “back has gone out” (where did it go?) or if you have had that unpleasant sensation of excruciating lower back pain that causes you to lie on the floor and cry for two days, there is a good chance that your psoas was in rebellion.
Studies have also shown a correlation between weak, underused psoas muscles and degeneration of other spinal muscles.
Chronicly tight hip flexors, in particular the psoas, can contribute to long-term spinal pain and can even pull the vertebrae out of place. The psoas can even affect chronic issues liks spondylolisthesis and spinal stenosis.
Two major factors that can contribute to tight hip flexors and cause the psoas to pull on the lower back are sitting for long periods of time and poor posture. Both of these activities can make the psoas squashed, weak, and tight. You can learn more about posture and hip tightness here, and see a posture tutorial here.
How to Take Care of Your Psoas to Prevent Lower Back Pain
The good news is that there are things that you can do to take care of your hip flexors and psoas to prevent lower back pain and injury. While stretching can play a part in this regimen, sitting in a lunge alone will not usually be enough. Lunges can be a great tool, but you have had the experience of sitting in lunges for hours only to find your hip flexors tighten right up afterwards, you will know that stretching alone is not enough to change the way that your hips work.
Most often there needs to be a combination of elements including improving the cooperation of the core muscles to improve the support of the spine, strengthening for the hip extensors (hamstrings and glutes), and a nice, loving targeted routine to strengthen and mobilize the psoas muscle so that it feels free and empowered. I have a routine that I have used for years and has greatly helped my lower back pain, in tandem with all of the other tools mentioned here, in this post on how to have a strong, flexible psoas.
Even though the psoas hip flexor is a difficult muscle to work with because if its internal position and how many different ways it can move, it is worth the investment since it has a profound effect on lower back pain and your long term spinal health.
Video for you visual learners…