Chiropractic Spinal Manipulation and Cauda Equina Risk

Cauda equina syndrome (CES) is an uncommon but serious neurological condition that requires prompt recognition and medical evaluation. Because chiropractors and physical therapists may be first-contact clinicians for patients with low back pain, sciatica, lumbar disc herniation, or spinal stenosis, questions about treatment safety and CES risk are clinically important.

A 2026 retrospective cohort study examined a specific question: among adults with lumbar disc herniation, lumbar spinal stenosis, or radiculopathy/sciatica, was chiropractor-administered spinal manipulative therapy (SMT) associated with a higher risk of CES than physical therapist-led therapeutic exercise (PTE)?

The study found no statistically significant difference in CES risk between the two matched cohorts. However, the findings should be interpreted as evidence about an association in a large observational dataset—not as proof that SMT and exercise are equivalent, or that either intervention can never be followed by CES.

Watch the ChiroSecure Research Update

Video overview: This ChiroSecure Research Update examines the 2026 study comparing chiropractor-administered spinal manipulative therapy with physical therapist-led therapeutic exercise and the subsequent risk of cauda equina syndrome in adults with lumbar disc herniation, stenosis, or radiculopathy.

The video provides the research presentation. The article below expands on the study design, results, limitations, clinical interpretation, and the importance of recognizing neurological red flags.

Why Was This Study Needed?

Case reports and medicolegal reports have described cauda equina syndrome occurring after spinal manipulation. Those reports can raise an important safety question, but they cannot by themselves determine whether manipulation caused the syndrome.

The problem is that patients seeking care for low back pain already have an underlying risk of developing CES. A temporal sequence—treatment followed by CES—does not necessarily establish causation.

Earlier observational research examined CES risk after chiropractic spinal manipulation among adults with low back pain. A 2024 PLOS ONE study involving 67,220 propensity-matched patients in each cohort found no evidence of an increased CES risk following chiropractic spinal manipulation compared with physical therapy evaluation without spinal manipulation. The authors noted that the population contained relatively few patients with lumbar disc herniation, sciatica, or spinal stenosis.

The 2026 study was designed to address that limitation by focusing specifically on adults with lumbar disc herniation, stenosis, and/or radiculopathy and by using therapeutic exercise as the active comparator.

What Did the 2026 Study Examine?

Trager, Baumann, Perfecto, and Goertz conducted a retrospective cohort study using the TriNetX research network. The investigators examined deidentified electronic health-record data from a large network of healthcare organizations.

The study included adults aged 18 years or older with one or more of the following:

Lumbar disc herniation
Sciatica or lumbar radiculopathy
Lumbar spinal stenosis

The researchers created two treatment cohorts:

Spinal manipulative therapy: SMT administered by a chiropractor.
Physical therapist-led therapeutic exercise: PTE without spinal manipulation.

The investigators excluded patients with preexisting CES, urinary or fecal incontinence, bladder catheterization, serious spinal pathology that could cause CES, recent spine surgery or injection, and several other conditions that could complicate interpretation.

Patients were then propensity-score matched to balance measured characteristics associated with CES risk.

What Were the Main Results?

Before matching, the researchers identified 34,434 patients in the SMT cohort and 630,160 in the PTE cohort. After matching, 34,376 patients remained in each group, with measured baseline characteristics adequately balanced.

During the three-month follow-up period:

Outcome	SMT cohort	PTE cohort
Patients after matching	34,376	34,376
Cauda equina syndrome	14	16
CES incidence	0.04%	0.05%
Risk ratio	0.88 (95% CI, 0.43–1.79; p=.715)

The difference in CES risk was not statistically significant. The study therefore did not identify an association between chiropractor-administered SMT and increased CES risk in this population.

The study also examined bladder catheterization and fecal incontinence as secondary outcomes. Both occurred less frequently in the SMT cohort. The risk ratio was 0.50 for bladder catheterization and 0.50 for fecal incontinence.

Those secondary findings should not be interpreted as evidence that SMT prevents CES or prevents bladder or bowel dysfunction. They were secondary observational outcomes and may be influenced by factors that cannot be fully controlled in electronic health-record data.

What Does the Risk Ratio of 0.88 Actually Mean?

This is an important point for interpreting the study accurately.

A risk ratio of 1.0 would indicate the same observed risk in both cohorts. The observed RR of 0.88 was below 1.0, but the 95% confidence interval ranged from 0.43 to 1.79 and the p value was .715.

In practical terms, the data did not establish a statistically significant difference between the groups. The confidence interval also shows why the study should not be described as proving that SMT is equivalent to exercise with respect to CES risk.

CES was rare in both groups. Only 30 cases occurred after matching. When an outcome is this uncommon, relatively small changes in the number of observed events can produce substantial uncertainty around the estimated effect.

What Are the Important Limitations?

The study has several strengths, including a large sample, an active comparator, propensity-score matching, a prespecified protocol, and a population specifically selected for lumbar conditions associated with CES.

It also has important limitations.

It was observational. Patients were not randomly assigned to SMT or exercise. Residual confounding therefore remains possible.
CES events were rare. The small number of events produced wide confidence intervals and limited precision.
Clinical detail was limited. The researchers could not review individual patient charts to determine all relevant clinical circumstances.
SMT technique could not be characterized. The dataset could not establish the specific thrust, patient position, force-time characteristics, or other biomechanical details of treatment.
Exercise could not be characterized in detail. The investigators could not determine precisely which therapeutic exercises individual patients received.
Residual confounding is possible. Important differences in pain severity, disability, symptom distribution, or other clinical factors may not have been fully captured by administrative and diagnostic codes.
Generalizability is limited. The data came from a U.S. healthcare network, and treatment pathways can differ in other countries.

These limitations do not invalidate the findings. They define what the findings can reasonably tell us.

Does This Study Prove That Chiropractic Manipulation Cannot Cause Cauda Equina Syndrome?

No.

The study did not identify an increased association between SMT and CES in the population examined. That is different from proving that CES can never occur after manipulation.

The distinction matters because observational research evaluates patterns of risk in populations. It cannot establish that a particular treatment could not contribute to a rare event in an individual patient.

The appropriate interpretation is narrower: within this large U.S. retrospective cohort of adults with lumbar disc herniation, stenosis, and/or radiculopathy, chiropractor-administered SMT was not associated with a statistically significant increase in CES risk compared with matched physical therapist-led therapeutic exercise.

Why Does Clinical Screening Still Matter?

The absence of an observed increased risk does not remove the need for careful assessment.

CES can develop in patients who initially present with low back pain or sciatica. Symptoms may evolve over time, and early presentations are not always obvious.

Clinicians should therefore distinguish between a research question about treatment-associated risk and the separate clinical responsibility to recognize a patient who may already have evolving neurological compromise.

For chiropractors, that means the history and examination remain central to treatment selection and triage.

What Are the Red Flags for Possible Cauda Equina Syndrome?

Cauda equina syndrome involves dysfunction of multiple lumbosacral nerve roots. Commonly recognized warning signs include bladder or bowel dysfunction, altered sensation in the saddle or perineal region, sexual dysfunction, and significant or progressive lower-extremity neurological deficits.

NICE recommends immediate referral for adults with severe low back pain radiating into the leg together with new-onset bladder, bowel, or sexual dysfunction or new-onset perineal numbness for assessment for CES.

The American Association of Neurological Surgeons likewise identifies urinary retention, urinary or fecal incontinence, saddle sensory disturbance, lower-extremity weakness, and sexual dysfunction among important CES warning signs.

In clinical practice, concerning findings can include:

New difficulty initiating urination
New loss of normal bladder sensation
New urinary retention or incontinence
New bowel dysfunction or loss of bowel control
New saddle, perineal, genital, or perianal sensory changes
Progressive or significant weakness affecting the lower extremities
New or rapidly worsening bilateral neurological symptoms
Sexual dysfunction accompanied by other concerning neurological symptoms

These findings warrant an appropriate urgent medical pathway rather than simply modifying a manual therapy technique.

What Does This Mean for Chiropractic Practice?

The study adds to a growing body of research examining the safety of spinal manipulation in patients with low back and lumbar-related disorders. It should be interpreted alongside, rather than in isolation from, clinical assessment, prior observational research, systematic reviews, and clinical guidelines.

ChiroSecure’s broader research coverage of low back pain similarly emphasizes that contemporary care does not require an either-or choice between manual therapy and active care. Current evidence supports incorporating appropriate exercise, education, activity advice, monitoring, and referral into individualized care.

A practical clinical framework includes:

Establish the clinical presentation. Distinguish nonspecific low back pain, referred pain, radicular symptoms, radiculopathy, stenosis, and possible serious pathology.
Perform an appropriate neurological assessment. Pay attention to symptom distribution, motor findings, sensory changes, reflexes when appropriate, and progression.
Screen for red flags. New bladder or bowel dysfunction, saddle sensory changes, progressive neurological deficits, significant trauma, infection, malignancy, and other serious findings require appropriate escalation.
Select treatment based on the clinical presentation. SMT may be one component of conservative management when clinically appropriate.
Include active care when appropriate. Exercise, education, activity modification, and self-management can complement manual therapy.
Reassess. Changes in neurological status, function, symptoms, or response to treatment should influence the care pathway.
Refer when indicated. Suspected CES or other serious neurological pathology requires appropriate urgent medical evaluation.

How Does This Fit With Earlier Research?

The 2026 study builds on a 2024 retrospective cohort study by the same broader research group. That earlier study included 67,220 propensity-matched adults with low back pain in each cohort and compared chiropractic spinal manipulation with physical therapist evaluation without spinal manipulation. It also did not identify an increased CES risk following SMT.

The newer study is particularly relevant because it focused on patients with lumbar disc herniation, stenosis, and/or radiculopathy and used therapeutic exercise as the active comparator.

This progression is important. Evidence becomes more clinically useful when research questions become increasingly specific to the population and exposure being studied.

Where Does Exercise Fit?

Physical therapist-led exercise was used as the comparator in this study because it represents an active conservative treatment rather than no treatment.

That does not mean the study tested every possible form of exercise or every physical therapy treatment. The researchers could not determine the precise exercise programs delivered to individual patients.

More broadly, ChiroSecure’s current review of low back pain evidence describes exercise and active self-management as important components of conservative care and notes that manual therapy can be combined with exercise when clinically appropriate.

The clinical question is therefore not necessarily “manipulation or exercise?” In many patients, the more useful question is how different evidence-informed interventions can be integrated around the patient’s diagnosis, goals, functional limitations, preferences, and response to care.

Frequently Asked Questions

Does chiropractic spinal manipulation increase the risk of cauda equina syndrome?

The 2026 retrospective cohort study did not identify a statistically significant increased risk of CES following chiropractor-administered SMT compared with matched physical therapist-led therapeutic exercise in adults with lumbar disc herniation, stenosis, and/or radiculopathy.

Does the study prove that chiropractic manipulation is completely safe?

No. The study evaluated an association in observational data. CES was rare, the confidence interval was wide, and the investigators could not fully measure clinical factors or treatment technique. The findings should therefore be interpreted as evidence against an identified increased association, not as proof that an adverse event is impossible.

How many patients were included?

After propensity-score matching, 34,376 patients were included in each cohort, for a total of 68,752 matched patients.

How many cases of cauda equina syndrome occurred?

There were 14 CES cases in the SMT cohort and 16 in the physical therapist-led exercise cohort during the three-month follow-up period.

What symptoms should raise concern for cauda equina syndrome?

Important warning signs include new bladder or bowel dysfunction, saddle or perineal sensory changes, sexual dysfunction, and significant or progressive neurological weakness. These findings require urgent medical assessment rather than routine continuation of conservative treatment.

Does lumbar disc herniation automatically mean spinal manipulation is inappropriate?

No such conclusion follows from this study. The research specifically examined adults with lumbar disc herniation, stenosis, and/or radiculopathy. Treatment decisions still require individual assessment, consideration of neurological findings and contraindications, and appropriate clinical judgment.

Should chiropractors use exercise with spinal manipulation?

Exercise and active self-management are important components of contemporary low back pain care. When clinically appropriate, chiropractors may incorporate exercise, education, activity advice, and manual therapy into an individualized care plan.

Key Takeaways

A 2026 retrospective cohort study compared chiropractor-administered SMT with physical therapist-led therapeutic exercise in adults with lumbar disc herniation, stenosis, and/or radiculopathy.
After matching, each cohort contained 34,376 patients.
CES occurred in 14 SMT patients and 16 PTE patients.
The observed risk ratio was 0.88 (95% CI, 0.43–1.79; p=.715).
The study did not identify a statistically significant increased association between SMT and CES.
The study does not prove that SMT and exercise are equivalent or that CES cannot occur after treatment.
The rarity of CES produced wide confidence intervals and limits precision.
Clinical assessment and recognition of neurological red flags remain essential.
New bladder or bowel dysfunction, saddle sensory changes, sexual dysfunction, or progressive neurological deficits require appropriate urgent medical evaluation.
Exercise, education, activity, monitoring, and referral can be incorporated into individualized conservative care when appropriate.

References and Evidence Sources

Trager RJ, Baumann AN, Perfecto R-PT, Goertz CM.
Chiropractic spinal manipulative therapy versus physical therapist-led exercise and the risk of cauda equina syndrome in adults with lumbar disc herniation, stenosis, or radiculopathy.
PM&R. 2026;18(7):723–734.
doi:10.1002/pmrj.70071.
Trager RJ, Baumann AN, Perez JA, Dusek JA, Perfecto R-PT, Goertz CM.
Association between chiropractic spinal manipulation and cauda equina syndrome in adults with low back pain: retrospective cohort study of US academic health centers.
PLOS ONE. 2024;19:e0299159.
doi:10.1371/journal.pone.0299159.
Bussières AE, Stewart G, Al-Zoubi F, et al.
Spinal Manipulative Therapy and Other Conservative Treatments for Low Back Pain: A Guideline From the Canadian Chiropractic Guideline Initiative.
Journal of Manipulative and Physiological Therapeutics. 2018;41(4):265–293.
doi:10.1016/j.jmpt.2017.12.004.
National Institute for Health and Care Excellence.
Suspected neurological conditions: recognition and referral.
NICE Guideline NG127.
American Association of Neurological Surgeons.
Cauda Equina Syndrome.

Primary study:
View the study on PubMed
or
read the open-access full text.

Clinical red flags:
NICE recommendations for suspected cauda equina syndrome
and
AANS information on cauda equina syndrome.

Explore More ChiroSecure Research

For additional evidence-informed discussion of low back pain and spinal manipulation, explore these related ChiroSecure research updates:

ChiroSecure also provides professional liability and risk-management resources for chiropractic practices. Visit the ChiroSecure website to explore those resources.

Conclusion

The 2026 evidence provides useful information about an important clinical safety question. In a large U.S. retrospective cohort of adults with lumbar disc herniation, stenosis, and/or radiculopathy, chiropractor-administered spinal manipulative therapy was not associated with a statistically significant increase in cauda equina syndrome compared with matched physical therapist-led therapeutic exercise.

At the same time, the study should not be overstated. CES was rare, the confidence interval was wide, and observational data cannot eliminate residual confounding. The study also could not characterize individual SMT techniques or specific exercise programs.

The practical lesson is therefore not that one profession or treatment should replace another. Rather, the evidence supports continued attention to appropriate patient selection, neurological assessment, informed consent, active care, reassessment, and timely referral when red flags appear.

For chiropractors and other first-contact clinicians, recognizing possible CES remains a critical part of safe clinical decision-making. When new bladder or bowel dysfunction, saddle sensory changes, sexual dysfunction, or progressive neurological deficits appear, the priority should shift from routine conservative management to appropriate urgent medical evaluation.

Educational disclaimer: This article is provided for professional education and general informational purposes. It does not provide individualized medical advice, diagnosis, or treatment and does not replace clinical judgment, applicable laws, professional standards, or individualized patient assessment. Healthcare professionals should evaluate each patient based on the complete clinical presentation and arrange appropriate referral or medical evaluation when indicated.