Lower back pain is the single leading cause of disability worldwide, affecting an estimated 619 million people in 2020. In the U.S., earlier estimates have placed the total annual cost of low back pain above $100 billion when medical expenses and indirect costs are considered. When it comes to diagnosis, attention often goes straight to the spine. Imaging can reveal a list of potential issues, including disc degeneration, arthritis, and disc bulges/herniations, to name a few.
But these findings do not always explain a person’s pain; degenerative changes are also commonly found on imaging in people without symptoms. However, when it comes to low back rehabilitation, patients are often surprised by how much we end up addressing weakness and mobility deficits in the hips. That relationship between hip mobility and lower back pain is one reason we need to look beyond the spine alone.
Your Spine is Meant to Move, but It Shouldn’t Have to Do All the Work
One of the hallmarks of LYT is the hip hinge: retraining clients to bend at the knees and hinge at the hips in lieu of folding forward. Many people wrongly assume that we shouldn’t flex the spine at all, which is far from the truth. For many people with low back pain, what we need more of is movement variability and load sharing.
The spine is meant to be mobile, but when a movement is repeated and muscle fatigue plays into the equation, we don’t necessarily want the lumbar spine to be the primary source of motion. We need to share the load.
The Research Behind Hip Mobility and Lower Back Pain
There is good biomechanical research that shows how repeated lumbar flexion during lifting can increase the load through the lumbar spine. Dolan & Adams (1998) found that over the course of 100 repetitive lifts with a 10 kg weight, the back muscles fatigued, lumbar flexion increased, and the bending moment acting on the lumbosacral junction increased 36%. Work on cadavers by Little and Khalsa in 2005 showed that repetitive lumbar flexion changes the mechanical behavior of the spinal soft tissues, including increased intervertebral motion and increased strain on the facet joint capsules.
Further research speaks to the relationship between the spine and lower extremities. Sparto et al. (1997) found that repetitive lifting resulted in lumbar fatigue, decreased hip and knee flexion, increased lumbar flexion, decreased postural stability, and decreased force-generation capability. Patterson et al. (2022) studied healthy young adults and found that females with less available hip flexion and lower lumbar extensor strength exhibited greater lumbar flexion during a squat-lifting task.
Finally, Takahashi and Yamaji (2020) looked at the influence of hip mobility on lumbopelvic rhythm, which is the coordinated movement of the hips, pelvis, and spine with normal bending, and how this may affect the lower back. They found that poorer hip flexibility altered lumbopelvic rhythm during forward bending, suggesting that limited hip mobility may be worth considering when looking at low back pain risk.
Bringing It to the Mat
Taken together, this research helps explain why LYT teaches the hip hinge over the forward fold. What happens in a traditional yoga class over and over again? The answer is repeated lumbar flexion in a forward fold. This is particularly true when we’re considering the traditional way the “swan dive” is taught, with the knees extended and all the motion coming from the flexion of the hips and the lumbar spine.
The literature suggests that we are better served in the low back to bend at the knees and hinge at the hips when folding forward repeatedly. The basic biomechanical concept is that more contribution from the hips and knees → better load sharing → less reliance on the lumbar spine during repeated forward folding. This allows the muscles of the lower extremities (particularly the glutes, hams, and quads) to share more of the work, potentially reducing repetitive demand on the back.
If a movement is repeated frequently, as is the case with forward folding in a yoga class (LYT or not), we generally want to distribute both the movement and the load across the larger and more capable joints and muscles of the hips and knees. However, this does NOT mean that you should never move or flex the lumbar spine. We just want to see the hips and knees be allowed to contribute their available ranges of motion to the equation.
Improving hip mobility can also give the body more movement options, allowing the hips to contribute rather than asking the lumbar spine to handle the movement alone.
The Takeaway Message
When we are looking at lower back pain, whether on the mat or not, we need to take a broader look. Often the spine isn’t the whole problem. It’s how we move as a whole. Training the body to move better through the hips and knees on the mat with a LYT hip hinge can help keep the lower back from being asked to handle repetitive movement on its own.
Do yourself a favor and stop asking your spine to do a job your hips and knees are designed to help with.
