Lumbar Lordosis

Quick answer: Lumbar lordosis is the natural inward curve of the lower back. Too much curve is called hyperlordosis; too little is called hypolordosis, or flat back.

Also called: lower-back curve, lumbar curve.

What is a normal lumbar lordosis?

Illustration comparing the inward curve of the lower back with the outward curve of the upper back

There’s no single “correct” curve. It varies from person to person and changes as you sit, stand and move. What matters more is whether the lower back can move in and out of its curve comfortably, and whether it’s balanced with the rest of the spine.

What changes the curve of the lower back?

Mostly the position of the pelvis beneath it. A forward-tipped pelvis (anterior pelvic tilt) tends to increase the curve, and a backward-tipped pelvis (posterior pelvic tilt) tends to flatten it. Long hours of sitting, the upper back’s position, and how the hips move all play a part.

How do I know if my lower-back curve is too much or too little?

Stand with your back against a wall and slide a hand behind your lower back. If your whole hand and forearm fit easily, the curve may be increased; if your hand barely fits, it may be flattened. This is only a rough check, and an assessment gives a clearer picture.

How is lumbar lordosis measured?

There is a measured answer, and the most useful thing about it is how wide it is. A review of normative values in the Journal of Manipulative and Physiological Therapeutics pulled together 26 studies and reported average lumbar lordosis on X-ray of about 44 degrees measured from L1 to L5, or 58 degrees from L1 to S1 — so the number depends on which vertebrae you measure between before anything else.

The ranges described as normal across those studies are startlingly broad:

What was reportedLumbar lordosisThoracic kyphosis
Older conventional range40–60°20–40°
Range found across studies31–88°22–68°
Normal range used by some authors30–80°10–40°

The reviewers’ conclusion on comparing methods was blunt: “No concordance among the results for both methods was shown.” Radiography and photogrammetry did not agree with each other, and the photogrammetry studies could not even be pooled because the procedures and calculations differed so much.

The practical consequence matters more than the numbers. If healthy lower backs span something like 30 to 80 degrees, and two measurement methods disagree, then being told your curve is “too much” on the basis of a single figure — particularly one estimated from a photograph — carries very little information. A curve well outside the usual range is worth a conversation. A curve somewhere in the middle of an enormous normal range is not a finding.

Does the size of your lower-back curve predict back pain?

Not in the direction most people expect. A systematic review and meta-analysis in The Spine Journal compared 796 people with low back pain against 927 healthy controls across 13 studies and found that the back-pain group had less lumbar curve than the controls, not more (SMD −0.33, 95% CI −0.46 to −0.21 in age-matched studies; −0.94 where disc herniation or degeneration was involved).

Read that carefully before acting on it. The age-matched effect is small, despite the authors calling the relationship strong. And every comparison is cross-sectional, measuring curve and pain at the same moment — so it cannot say which came first. A lower back that has hurt for years is commonly held flatter and more rigidly, which would produce precisely this result without the flatness having caused anything.

What it does mean is that the widespread advice to flatten an “excessive” lumbar curve is pointed in the opposite direction from the best available comparison. The honest position is that the angle is a poor guide on its own, and what the lower back can comfortably do matters more than the number it sits at.

Can exercise change the curve in your lower back?

Less reliably than you would expect, and there is a clean comparison available. A meta-analysis in PLOS ONE assessed exercise programs against both spinal curves. For thoracic kyphosis the pooled improvement was large and significant (SMD −1.40). For lumbar lordosis the change was moderate and not statistically significant (SMD −0.53, p = 0.401, four trials).

Same review, same methods, two outcomes, and the lower back is the one that did not shift. The authors suggested both strengthening and flexibility matter for the lumbar curve, rather than strengthening being clearly more relevant as it appeared to be for the upper back. The reasonable takeaway: exercise is worth doing for how the lower back feels and functions, and the angle itself is not a promise anyone should make.

What Does Change, and by How Much

So the curve is a poor guide and it does not move much. That raises the obvious question of what does respond, and that question has a much better answer.

The evidence base for exercise and movement in persistent low back pain is far larger than the evidence base for any postural measurement, and it is worth putting the two side by side. A Cochrane review pooled 249 trials and 24,486 participants. Against no treatment, usual care or placebo, exercise reduced pain by 15.2 points on a 100-point scale (95% CI −18.3 to −12.2), with moderate-certainty evidence, and that difference is large enough to matter to the person feeling it.

What was measuredChange with exerciseEvidence behind it
Pain (0–100 scale)−15.2 points, clinically important249 trials, 24,486 participants
Day-to-day function6.8 points, a real improvementSame review
The lumbar curve angleNot the number that tracks progress (no significant change, p = 0.401), which is why progress is measured in pain and function4 trials

Read that table as an instruction about what to measure. The angle is the outcome that does not reliably move. Pain is the outcome that does. A program judged on a photograph is being judged on the one thing least likely to change; a program judged on what hurts and what you can do is being judged on what the research says actually shifts.

Two honest qualifications, because the headline figure is specifically about exercise versus doing nothing. Compared with other active treatments the differences were smaller and did not reach the clinically important threshold, and exercise showed no advantage over manual therapy. It did beat education alone and electrotherapy. So the strong claim is that moving deliberately beats not moving — which is the comparison most people are actually choosing between.

On what kind of movement, a network meta-analysis of 217 trials and 20,969 participants found Pilates, McKenzie-style work and functional restoration produced the largest improvements, with Pilates reducing pain by 18.7 points (95% CI −24.4 to −13.1) against minimal treatment. But the authors’ closing advice is the part worth taking to heart: people with chronic low back pain “should be encouraged to perform the exercise that they enjoy to promote adherence.”

Which is why the useful targets are not shapes. What responds to this kind of work, and what is worth assessing and re-assessing, is: how much range of motion you have and whether it is comfortable through the whole of it; how much strength you have and where it runs out; how well the right muscles coordinate and fire when you load a position; how readily you learn a new movement pattern and hold onto it; and how much you can do before something complains. Those change, they are measurable, and they are what a person actually notices.

Sources

Related terms

Learn more and take the next step

For an exaggerated lower-back arch, see our hyperlordosis guide. For a flattened lower back, see flat back.

If you’d like someone to look at what’s driving your posture, a free 30-minute consultation starts with a postural assessment, in one of our clinics or through virtual posture therapy.

This entry is general education, not medical advice. If you have pain, numbness, weakness, or a change in your posture that appeared quickly, see a physician first.

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