Back Pain But Your MRI Looks Normal? Three Things to Check

Persistent back pain. A lumbar MRI that comes back clean. A specialist who shrugs and says everything looks fine. This is one of the most frustrating experiences in spine care — and it happens more often than it should.

A normal MRI does not mean nothing is wrong. It means the MRI didn’t find it. An MRI of the lumbar spine is taken lying flat on your back, in a magnet, in a relaxed position. It is excellent at showing disc herniations, nerve compression, and cord pathology. It is not a complete spine workup. Several significant causes of back pain are invisible on a supine MRI — and are found only with the right additional imaging or a thorough physical examination.

What a supine lumbar MRI reliably finds — and what it misses
Found on MRI Disc herniation & nerve compression

The MRI’s primary strength — clearly identified even in the supine position.

Often missed on supine MRI Positional spondylolisthesis

A vertebral slip that reduces completely when you lie flat — visible only on standing X-rays.

Found on MRI Stenosis & cord pathology

Canal narrowing, cord signal change, and tumors are reliably seen on MRI.

Invisible on any imaging SI joint dysfunction · Muscular pain · Facet pain

Clinical diagnoses. No scan finds them. Only examination and targeted injections do.

Found on MRI Infection & tumors

Discitis, osteomyelitis, and spinal tumors are well-detected by MRI with contrast.

Missed — different imaging needed Sagittal imbalance · Bertolotti · Baastrup

Require standing X-rays, CT, or SPECT-CT to identify. Often overlooked entirely.

Here are the three things that should be checked when the MRI comes back clean.


01
Thing 1 — Imaging you haven’t had yet Standing X-rays —
upright, loaded, and in motion

An MRI is taken lying down. It shows your spine at rest, unloaded, with the muscles relaxed. Standing X-rays show your spine the way it actually functions — upright, bearing weight, with gravity doing what gravity does. Two completely different pictures of the same spine.

Full-length standing X-rays for sagittal and coronal balance. When you stand, your spine should be aligned so your center of gravity falls in a specific relationship to your pelvis. If you lean forward (positive sagittal imbalance), backward, or to one side (coronal imbalance), the muscles of your back fire constantly to prevent you from falling. That sustained muscular effort is painful. It produces diffuse axial back pain that worsens through the day and has no disc herniation, no stenosis, and a clean MRI. The only way to see it is a full-length standing X-ray from the skull base to the femoral heads.

Sagittal & coronal imbalance — what they look like and why they hurt
Balanced Gravity line through pelvis. Muscles at rest. No compensatory pain.
Forward lean
(+ sagittal imbalance)
Back extensors fire all day to keep you upright. Aching pain that builds through the day.
Side lean
(coronal imbalance)
One-sided trunk muscles chronically overloaded. Unilateral back pain. Clean MRI.

Why the MRI misses this: You are lying flat. The gravitational load that drives compensatory muscle firing is gone. The spine looks relaxed — because in that position, it is.

Flexion-extension X-rays for dynamic instability. These are lumbar X-rays taken with you bending actively forward and then backward. They reveal whether any vertebra slips on its neighbor during movement — something a supine MRI cannot show. A vertebral slip that appears only under load or motion (dynamic spondylolisthesis) is a well-recognized cause of back pain that disappears completely on the supine scan. The bones look perfectly aligned lying down. On the flexion X-ray, one slips forward. That is the diagnosis.

What flexion-extension X-rays find that the MRI cannot
Supine MRI Bones appear aligned. No slip. Normal study. Workup feels complete — but you’re still in pain. ✓ Clean but incomplete
Flexion X-ray Bending forward loads the anterior column. A slip becomes visible that reduced at rest. Dynamic spondylolisthesis identified. Catches anterior slip
Extension X-ray Bending backward loads the posterior elements. Retrolisthesis or instability under extension may appear for the first time. Catches retrolisthesis

02
Thing 2 — What the physical exam finds that no scan does Clinical examination for
non-disc pain generators

Several of the most common causes of back pain produce no imaging finding at all. They are diagnosed entirely through the physical examination, the pattern of symptoms, and the response to targeted injections. If the clinician is not specifically looking for them, they will be missed every time.

Four pain generators that require a clinical exam to find
Muscular
Myofascial pain & paraspinal muscle guarding Diffuse aching in the paraspinal, gluteal, and hip rotator muscles. Palpable trigger points. Worsened by stress and prolonged posture, improved with movement. No imaging finding. Extremely common, frequently overlooked, and sometimes the primary pain generator. Physical therapy, dry needling, and myofascial release are effective.
Facet joints
Facet arthropathy — zygapophyseal joint disease Axial back pain worsened by extension, standing, and rotation. Refers into the buttock and posterior thigh but rarely below the knee. May appear mildly on MRI or not at all. Confirmed with medial branch nerve blocks; treated with radiofrequency ablation if blocks are positive. One of the most common causes of chronic low back pain in adults over 50.
Discogenic
Degenerative disc disease without herniation Internal disc disruption causes axial loading pain — worsened by sitting, flexion, and Valsalva. MRI may show only mild desiccation and modest height loss. The disc is the pain generator, but there is no herniation and no nerve compression. Provocative discography can identify the specific level when multiple discs are mildly degenerated and the clinical exam cannot distinguish them.
SI Joint
Sacroiliac joint dysfunction Pain at the joint connecting the sacrum and ilium — felt in the lower back, buttock, and sometimes upper thigh. Accounts for an estimated 15–25% of chronic low back pain. No imaging finding identifies it. Diagnosed through provocation maneuvers on examination and confirmed by fluoroscopy-guided injection. See the SI examination tests below.
SI joint provocation maneuvers — how the exam is done
Fortin finger
Patient points to pain with one finger When the finger consistently lands just medial to the posterior superior iliac spine (PSIS), this pattern is highly specific for SI joint origin. Reliably reproducible on repeated testing in true SI pain.
FABER test
Figure-4 hip position with gentle knee pressure Reproduction of posterior pelvic or buttock pain (not groin pain) suggests SI joint involvement. Groin pain points to the hip joint instead.
Thigh thrust
Posterior shear through the femur with hip at 90° Creates a posterior shearing force through the SI joint. Reproduction of familiar buttock pain is a positive test — one of the highest-specificity maneuvers for SI joint pathology.
Injection
Fluoroscopy-guided SI joint injection — the confirming test Two positive provocation maneuvers plus >75% pain relief following a fluoroscopy-guided local anesthetic injection confirms the diagnosis. No imaging needed. The injection is both diagnostic and often therapeutic when combined with corticosteroid.

03
Thing 3 — When you’re still stuck Advanced imaging —
and the uncommon diagnoses

Standing X-rays are normal. The clinical examination for muscular pain, facet disease, SI joint, and discogenic pain has not identified the source. The workup has been thorough and has not found an answer. At this point there is one more imaging tool worth knowing about before reaching for rare diagnoses — and then two specific structural variants that are real, underrecognized, and worth looking for specifically.

CT lumbar spine merged with nuclear medicine SPECT
Standard MRI or CT

Shows anatomy — what structures look like. Cannot tell you which of three mildly degenerated facet joints, if any, is the one causing pain. A painful joint and an asymptomatic one look the same.

SPECT-CT (functional + anatomical)

Shows anatomy plus metabolism — where active bone turnover and inflammation are occurring right now. Increased radiotracer uptake at a specific joint or endplate identifies the metabolically active structure. That is the pain generator the standard imaging cannot isolate.

When SPECT-CT is most useful:

Multi-level facet arthropathy — isolates which level is metabolically active and should be targeted with medial branch block
Suspected Bertolotti syndrome — uptake at the pseudoarticulation confirms it as the active pain generator
Equivocal SI joint examination — metabolic activity at the joint supports the diagnosis when exam findings are borderline
Occult stress reaction or early spondylolysis not yet visible on standard MRI or CT
The key insight: SPECT-CT does not replace MRI or CT — it adds a metabolic layer. When standard imaging shows multiple degenerated structures and the examination cannot isolate the painful one, the SPECT signal points to where the biology is active. That is the structure to treat.

When SPECT-CT or targeted X-ray review is performed, two structural diagnoses are worth having on the radar specifically because they are frequently present in the population, frequently painful, and frequently missed on standard reads:

Uncommon but underrecognized

Bertolotti Syndrome

A congenital variant in which the transverse process of L5 is enlarged and forms an abnormal articulation with the sacrum or ilium. This transitional lumbosacral segment alters mechanics at L4-L5 and the SI joint, and can cause significant low back pain disproportionate to MRI findings. Present in approximately 4–8% of the population. Visible on X-ray and CT but easily overlooked. SPECT-CT tracer uptake at the pseudoarticulation confirms it as the active pain source.

Clinical clue: Younger patient, chronic unilateral or bilateral low back pain, active lifestyle, relatively normal MRI, asymmetric lumbosacral junction on X-ray.
Uncommon but underrecognized

Baastrup Disease
("Kissing Spine")

Abnormal contact between adjacent spinous processes in a hyperlordotic lumbar spine. The contact causes bursa formation, inflammation, and midline back pain worsened by extension and relieved by flexion. Visible on lateral X-ray and MRI as spinous process contact with edema, but easily dismissed as incidental rather than recognized as the pain source. Targeted injection or surgical resection of the offending spinous process can provide relief.

Clinical clue: Midline (not lateral) low back pain, distinctly worse with standing and extension, relieved by sitting and bending forward. Lateral X-ray shows narrow interspinous distance or frank contact.

“A normal MRI is the beginning of a workup, not the end of one. The question is not whether the scan looks clean — it is whether the right structures have been examined.”

Persistent back pain with a normal lumbar MRI is not imaginary and it is not untreatable. The three steps above complete the evaluation the MRI leaves out: standing X-rays with flexion-extension views to find what only load and motion reveal; a thorough clinical examination for muscular pain, facet disease, SI joint dysfunction, and discogenic pain that no scan identifies; and advanced imaging with SPECT-CT when the source is still unclear, with specific attention to Bertolotti and Baastrup on the structural review.

If you have been told your MRI is normal and sent home without these steps — the workup is not finished. A second opinion that covers all of this is the appropriate next step.

Still in pain with a normal MRI?

Bring your imaging and X-rays if you have them. Describe exactly where the pain is and what makes it better or worse. Telemedicine available from anywhere in Florida. The workup starts where the MRI left off.

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