I cannot count the number of times through the years when I encounter patients, friends, and family members who present with little to no lumbar extension (bending backwards motion coming purely from the low back segments, L1-L5). It is often the key starting point to determining what will be done with an individual experiencing low back pain or lower extremity weakness. Why is that the case, you ask? Because pain (numbness, tingling, burning) that travels from the lower back to anywhere below your belt line (sciatica) is very commonly coming from lumbar spine discs whose integrity has been affected. The discs are either compressing a spinal nerve or the outer layers of the disc are damaged and not compressing a spinal nerve (yes, you heard that right, and it’s either one). Either scenario will cause the muscles of the back or lower extremities not to fire on all cylinders. Often observed in practice, you will see a person with insufficient lumbar extension, which, according to AnatomyStandard.com’s meta-analysis on the theoretical normal spinal range in healthy male adults, is about 30 degrees. I’d say most individuals I come across don’t get even close to that number.
Who Cares?
But so, what, right? Who cares? How does that affect you? Well, for one, if you have low back pain or pain in the distal extremities (where referring pain originates from the spine, 20-43% of the time, according to Rosedale et al., 2019). The ability to resolve your low back pain will come, to a certain extent, from restoring lumbar extension. Restoring lumbar extension will allow a disc that has been damaged to be able to heal itself and/or stop it from compressing on a spinal nerve root that is causing pain to travel into your limbs (sciatica). That is a super simplified explanation. There is nuance, and it takes multiple steps. If you have got the time, try to piece it together on YouTube or through your own research, go for it. If you don’t want to give up your most valuable currency of time, maybe you should seek help from clinicians who deal with this daily. Sure, it makes sense when you get pain, but what if you’re healthy? No harm, no foul, right? Not exactly.
What If I Have No Back Pain? How Does Not Having Lumbar Extension Affect Me Functionally?
Great question, because this often comes as a surprise for many when it is expressed that weakness in the extremities comes from the spine, EVEN WHEN THERE IS NO PAIN FELT FROM THE NECK, MIDBACK, OR LOW BACK AREA. Let’s think about this logically. If my shoulders, arms, hands, thighs, legs, and feet are experiencing weakness without pain in the spine or in the limbs that are involved, am I going to be able to function fully, to the best of my physical potential? The answer is an emphatic no. Countless times in my career, I have observed patients with a lumbar extension of 0 degrees have weakness at the 4th and 5th spinal nerve levels with associated weakness at the muscles they innervate, only for them to improve with restoring lumbar extension. Numbers don’t lie, the closer you get to theoretical normal (30 degrees), and it’s a spinal disc issue that can be changed positively with exercise, the strength from improved neural connection (fancy term for the spinal nerve roots are no longer irritated) improves, often very quickly. But don’t just take my word for it. Look at the research.
The Need for Lumbar Extension for Optimal Speed and Strength
Personally, I would fall into the category of individuals who have a stiff lumbar spine and lack lumbar extension. This, without a doubt, puts me at a higher risk of sustaining a low back injury that is disc-related, which occurred in 2023, when I herniated spinal discs L4 and L5. Through only exercise, I was able to make a full recovery. Interestingly enough, having extensibility of the lumbar spine closer to the theoretical normal of 30 degrees goes beyond just injury prevention. It actually is needed to ensure maximal performance in athletic activities, most notably running. Studies performed by Tojima et al (2019) and Tomianga et al (2025) found that as healthy runners increased their speed, lumbar extension had to increase in order to attain those higher speeds. Tojima’s study recorded a change from 18.3 degrees of lumbar extension at 3.73 miles per hour to over 22 degrees at 7.46 miles per hour, as well as reduced time the contacting foot spent on the ground (Stance Phase), which was reduced by 18-22%. The less time your feet are on the ground, the more efficient and quicker your running becomes.
Tomianga’s 2025 study took this further, showing lumbar lordosis (the curve created by spine extension) rising predictably with increased running speed among healthy male athletes. Lumbar spine extension is not only needed for increased stride length (the length of distance covered from when your foot leaves the ground to the same foot landing again), but also to cushion against forces coming up from the ground upon impact that can ultimately compress the spine. The spine is like a spring; without the ability to extend (arch back), the forces will cause more wear and tear on the spine over time, much like landing vertically with a straight, rigid pencil that is more likely to crack rather than a shock-absorbing spring, which dissipates the forces coming up from the ground like a champ.
If lumbar extension is way below that healthy benchmark of about 30 degrees, as referenced in clinical meta-analyses and repeatedly encountered in the population, both pain and performance will eventually suffer. Reestablishing extension not only relieves pressure on the sensitive spinal nerves to resolve sciatica, but it also reestablishes proper nerve communication between the spine and limb muscle, which can rapidly restore strength. As always, there are nuances, and individuals who don’t have much disc height left may not benefit.
Take Away Message
Research and daily clinical practice clearly show that restoring lumbar extension is foundational not just for pain relief but to maximize strength and speed for individuals. If optimal function and performance are the goal, neglecting lumbar spine mobility in extension simply isn’t an option in modern musculoskeletal care or performance enhancement. If you need further guidance, do yourself a favor. Stop overthinking. Reach out and get the timely help that you need for both injury and performance maximization.
Resources:
Anatomy Standard. (2022). Range of the Motion (ROM) of the Cervical, Thoracic and Lumbar Spine in the Traditional Anatomical Planes. Available at: https://www.anatomystandard.com/biomechanics/spine/rom-of-spine.html (Accessed: 17 September 2025)
Rosedale R, Rastogi R, Kidd J, Lynch G, Supp G, Robbins S, A study exploring the prevalence of Extremity Pain of Spinal Source (EXPOSS), J Man Manip Ther., published online, 2019.
Tojima, M., Osada, A., Torii, S., 2019. Changes in hip and spine movement with increasing running speed. J Phys Ther Sci 31, 661–665.
Tomianga, T., Tasaki, Y., Sado, N., 2025. Speed-dependent increase in lumbar lordosis is independent of anterior pelvic tilt and lumbo-pelvic extension during treadmill running. Journal of Biomechanics 186, 112715.
