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Do Patients With Low Back Pain Actually Have Stiffer Muscles?

July 3, 2026
Author: Harrison Shu

Sometimes, and it depends entirely on which muscle you measure and which tool you use. Deep tissue methods often find elevated stiffness in the lumbar multifidus of chronic low back pain patients, while surface methods often find no difference at all. The honest answer is that stiffness and pain are related but far from interchangeable, so a stiffness reading may reflect part of the picture and not the whole of it.

Chiropractor assessing a low back pain patient's paraspinal muscles

Does the research say low back pain patients are stiffer?

It splits along the method used. When the muscle is read with shear wave elastography, which reaches deep tissue, the answer tends toward yes. A 2024 study in Frontiers in Bioengineering and Biotechnology found that patients with chronic non-specific low back pain had significantly higher stiffness in the multifidus, erector spinae, and thoracolumbar fascia at the L4 to L5 level, and that stiffness correlated with reported pain intensity.

When a superficial method is used, the answer often flips. A 2024 myotonometry study in the International Journal of Sports Physical Therapy measured the lumbar multifidus and longissimus in physically active adults and found no significant difference in absolute muscle stiffness between the low back pain group and controls, despite good to excellent test-retest reliability of the readings themselves.

Why do two studies disagree about the same muscle?

Because they are not really reading the same tissue. Shear wave elastography penetrates to the deep multifidus. Myotonometry reads the layer close to the skin. Depth, posture, activity level, and how chronic the pain is all shift the result. Two careful studies can both be correct and still point in opposite directions.

Method Tissue depth read Typical low back pain finding
Shear wave elastography Deep (multifidus, fascia) Often elevated stiffness
Myotonometry Superficial paraspinals Often no absolute difference
Manual palpation Surface, subjective Highly rater-dependent

Does more stiffness mean more pain?

Not in a way you can rely on. A 2019 individually controlled study of 40 patients with chronic neck and back pain found the most painful site was often not the stiffest site, and the painful side was not stiffer than the pain-free side. Stiffness may indicate a mechanical change, but it does not map cleanly onto where or how much a patient hurts.

The timing is also loose. A 2025 study in the Journal of Bodywork and Movement Therapies found objective stiffness readings in the gastrocnemii stayed elevated even as subjects reported less soreness after delayed-onset muscle soreness. Feeling better may arrive before the tissue returns to baseline, which means a single stiffness number and a single pain score can tell different stories on the same day.

Survey data: In a 2026 survey of 455 patients who stopped chiropractic care early, 58% cited perception-based reasons: 36% felt no progress, and 22% felt better and self-discharged. A patient who judges their back by feel alone is working from a signal that may not match what the tissue is doing.

So is measuring stiffness worth it?

Yes, but for a narrower reason than "stiff equals hurt." The value is not in comparing one patient to a population where the evidence is mixed. The value is in comparing a patient to their own baseline over time. A reading that has dropped from a starting point, or one that is still elevated while pain has quieted, gives you something concrete to show that patient. That within-person change is where an objective number earns its keep, regardless of how the population-level debate settles.

Frequently Asked Questions

Do low back pain patients have stiffer muscles?

Sometimes, and it depends on the muscle and the method. Shear wave elastography often finds elevated stiffness in the deep multifidus. Myotonometry of the superficial paraspinals frequently finds no difference. There is no single answer across every muscle and tool.

Does higher muscle stiffness mean more pain?

Not reliably. A 2019 controlled study found the most painful site was often not the stiffest, and the painful side was not stiffer than the pain-free side. Stiffness and pain can move together or apart.

Why do different studies reach different conclusions?

They measure different tissue. Shear wave elastography reads deep muscle, myotonometry reads superficial layers. Different depths, postures, and populations produce different results, which is why the literature looks mixed.

Can a patient feel stiff without measuring stiff?

Yes. The sensation of stiffness is produced by the nervous system and does not always track the mechanical property of the tissue. A back can feel tight while an objective reading sits in a normal range.

If the evidence is mixed, why measure stiffness at all?

Because a within-patient change from their own baseline is more useful than a population comparison. It gives you a concrete data point to show the patient even when group-level differences are unclear.

Which method should a chiropractor use?

Shear wave elastography needs ultrasound and training but reaches deep tissue. Myotonometry is handheld and chairside but reads superficial muscle only. The right choice depends on which muscles matter and how fast you need a reading.

Citations

One approach is to add a second channel of objective data alongside subjective pain reports. Options include soft tissue stiffness measurement (such as MuscleMap), range-of-motion testing, and posture analysis. Each gives you something concrete to show the patient rather than asking them to take your word for it.