Chiropractic Care and Vascular Safety:
Updating the Science

Spinal Manipulation/Adjustment

Joints have three distinct ranges-of-motion (1).

1. Active Motion is the range that people can do on their own.
2. Passive Motion is the range that people can do with stretching, or another person can assist them with.
3. Periarticular Paraphysiological Space motion requires joint manipulation.

All of these motions are accomplished without any injury to joint tissues (muscles, ligaments, cartilage, nerves, etc.).

As noted, the third range-of-motion is termed the periarticular paraphysiological space range. Movement into this range requires a passive “push,” termed joint manipulation. Movement into the periarticular paraphysiological space range-of-motion with joint manipulation is often accompanied with an audible, palpable sensation that is both heard and felt; often this is described as a “pop” or “crack.” Contemporary explanations for these sensations are a mechanical development of a gas bubble (carbon dioxide) (2).

Movement into this periarticular paraphysiological space range requires a passive “push” or “thrust,” termed manipulation. Any person can perform joint manipulation, including lay people, as well as professionals (chiropractors, osteopaths, physical therapists, and others). The best recognized class of professionals that use manipulation are chiropractors.

Chiropractic manipulation is different when compared to others that manipulate. It employes a specific line-of-drive (direction of the “push” or “thrust”). Chiropractors refer to this specific line-of-drive manipulation as the chiropractic adjustment. Because of their training and the use of the spinal adjustment, chiropractic has an incredible safety record (3, 4).

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Vascular Anatomy

Vascular anatomy pertains to blood flow. All blood flow begins with the heart. The heart pumps the blood throughout all the regions of the body. The only spinal region with the potential for a vascular injury is the cervical spine (neck).

The heart pumps blood through the cervical spine to the brain using two arteries: the carotid and the vertebral:

• The carotid artery is located in the front of the neck, and it supplies the anterior circulation to the brain. Credible publications indicate that there is no risk of carotid artery injury from cervical spine chiropractic adjusting (3). For example, in 2017, the Journal of Stroke and Cerebrovascular Diseases published a study titled (5):

Risk of Carotid Stroke after Chiropractic Care:
A Population-Based Case-Crossover Study

The authors of this study assessed nearly 110,000,000 person-years over a period of 9 years, and concluded:

“We found no excess risk of carotid artery stroke after chiropractic care.”

“To date, there are no reported cases of stroke as an adverse event in the published trials of cervical spine manipulation.”

•••

The Vascular Supply to the Brain

The vertebral artery supplies the posterior circulation to the brain, including the cerebellum and brainstem. The vertebral artery is unique and interesting because it travels inside of the transverse processes of the cervical vertebrae C6 through C1 before entering the skull through the foramen magnum.

Recent Vascular Safety Studies

Recently, two large studies have looked at the safety of chiropractic adjustments and spinal manipulation (3, 4).

The first study was published in 2022 in the journal Healthcare, and titled (3):

Safety of Chuna Manipulation Therapy
in 289,953 Patients with Musculoskeletal Disorders:
A Retrospective Study

Chuna manipulation therapy (CMT) is a form of manual therapy employed by Korean medical doctors. It involves traditional joint manipulation, like that in chiropractic. Chuna manipulation was adapted from the chiropractic adjustment and encompasses manipulation techniques that employ “high-velocity, low-amplitude and thrust.” As in chiropractic, it is used to treat structural or functional pathologies. It emphasizes the balance between function and structure.

This type of manual therapy has been incorporated into the Korean health care system and has been administered in 16% of inpatients and 84% of outpatients with musculoskeletal disorders in Korean medicine hospitals specializing in spine and joint diseases. The authors note:

“Manual therapy is performed in various forms by chiropractors, osteopaths, and physical therapists across the world, including the United States, Europe, and Australia.”

“The use of spinal manipulation has increased in recent decades in Western countries, as has the popularity of chiropractic therapy among American adults.”

“The UK National Institute for Health and Clinical Excellence guidelines now recommend manual therapy for treating persistent or subacute lower back pain.”

This study assessed 2,682,258 manipulation procedures that were performed on 289,953 patients from 14 different facilities. The authors state:

“In this study, 289,953 patients and more than 2.5 million cases of CMT were reviewed, making it a rare, very wide-ranging, and reliable investigation of severe adverse events.”

The authors consider their analysis to be exceptionally accurate because Korean medical doctors check for adverse events at every patient visit, and nurses communicated with patients before and after each treatment to follow up on their post-treatment status.

Important for this discussion, there were no vascular injuries. The authors state:

“Adverse events of any level of severity were very rare after CMT.”

“There were no instances of carotid artery dissection or spinal cord injury.”

“No life-threatening or severe adverse events were observed that would support previous [artery injury/stroke] concerns.”

•••

The second study was published in 2023 in the journal Scientific Reports and titled (4):

A Retrospective Analysis
of the Incidence of Severe Adverse Events
Among Recipients of Chiropractic Spinal Manipulative Therapy

This study examined the incidence and severity of adverse events in 54,846 patients who received 960,140 chiropractic spinal adjustments. Study data originated from 30 chiropractic clinics using 38 different chiropractors.

This study is also massive. It represents one of the largest to examine potential spinal manipulative therapy-related adverse events. The authors concluded:

“In this study, severe spinal manipulative therapy-related adverse events were reassuringly very rare.”

“There were no adverse events related to stroke or cauda equina syndrome.”

“There were no cases of stroke, transient ischemic attack, vertebral or carotid artery dissection, cauda equina syndrome, or spinal fracture.”

It is also noteworthy that this study was published in the journal Scientific Reports. Scientific Reports is a top tier Q1 (top quartile) journal that is owned by Nature Publishing. At the time of publishing, Scientific Reports was the 5th most referenced journal in the world.

These studies continue to document the incredible safety of chiropractic care (3, 4). Severe adverse reactions are nearly unheard of. Minor reactions such as soreness are also incredibly rare and are self-limiting. The only noteworthy precaution is the potential to fracture ribs in the elderly, primarily women, usually with known osteoporosis. Yet, rib fractures are also incredibly rare and are self-limiting. Each chiropractic provider, depending upon the nature of their techniques and patients, should construct the appropriate informed consent for their practice.

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Older studies specifically looking at the risk of vertebral artery injury as related to chiropractic adjustments show that such events are extremely rare, and perhaps nonexistent. As an example, in 2001, the Canadian Medical Association Journal published a study titled (6):

Arterial Dissections Following Cervical Manipulation:
The Chiropractic Experience

The lead author, Scott Haldeman, is a historic and contemporary giant in the chiropractic profession. His list of accomplishments includes a chiropractic degree (DC), a medical degree (MD), a PhD, and a DSc. Dr. Haldeman is a clinical professor of neurology at the University of California, Irvine.

The authors of this study reviewed all malpractice data from the Canadian Chiropractic Protective Association to evaluate all claims of stroke following chiropractic care over a 10-year period. This data was compared with the number of cervical manipulations performed each year by chiropractors covered by the Canadian Chiropractic Protective Association.

The findings were:

• There were 23 cases of stroke or vertebral artery dissection following cervical manipulation reported during this 10-year period, or 2.3 cases per year. An analysis of these numbers revealed:
  • 1 event per 8.06 million chiropractic office visits
  • 1 event per 5.85 million chiropractic cervical manipulations
  • 1 event per 1,430 chiropractic practice years
  • 1 event per 48 chiropractic practice careers

The authors concluded:

“[These numbers are] significantly less than the estimates of 1 per 500,000–1 million cervical manipulations calculated from surveys of neurologists.”

An informative article pertaining to cervical artery injury was published in the journal Cephalalgia in 2022, and titled (7):

Head/Neck Pain Characteristics After
Spontaneous Cervical Artery Dissection
in the Acute Phase and on a Long Run

These authors “present an in-depth analysis of spontaneous cervical artery dissection-related head/neck pain characteristics and its long-term dynamics” in 279 patients, with a median follow-up of 6.5 years.

Spontaneous cervical artery dissection subjects were included if mural hematoma was visualized through T1 fat-saturated MRI at baseline; this strict inclusion criteria in the acute phase was obligatory, therefore generating a cohort consisting of subjects with definitive sCeAD diagnosis.

Important points from this article pertaining to the vertebral artery include:

• Head/neck pain are the primary symptoms associated with spontaneous cervical artery dissection.
• The head/neck pain was novel, different from all prior experience with head/neck pain.
• The pain onset is always sudden in every patient.
• Once the pain begins, it is continuous in all patients, but resolves in about 2 weeks.
• The neck pain is located in the superior postero-lateral region.
• The head/neck pain rarely responded to self-administered analgesic medications.
• “Pain quality in vertebral artery dissection was mostly of pulling nature (57%) and mostly dull-throbbing (47%) in anterior circulation sCeAD.”
• Accompanying symptoms such as nausea, photophobia, and phonophobia are rare.

•••••

Earlier this year (2026), another informative article pertaining to cervical artery injury was published in the journal Stroke & Vascular Neurology and titled (8):

Risk Factors for Cervical Artery Dissection [CAD]:
A Systematic Review with Meta-Analysis

This is the first review that comprehensively examined the risk of CAD in the general population. The authors evaluated 128 studies from a comprehensive literature search. Their findings include:

Certainty of Evidence that these Factors Result
in Increased Risk for CAD

• The most likely risk factors, with only moderate evidence, was a history of migraine headaches, and elevated levels of the amino acid homocysteine as related to mutations in the MTHFR gene.

Pertaining to spinal manipulation and cervical artery injury risk, the authors state:

“Our findings suggest that cervical spinal manipulative therapy is not a significant risk factor for CAD.”

•••••

Most recently, in September of 2026, a study was published in the journal Chiropractic & Manual Therapies and titled (9):

Association Between Spinal Manipulative Therapy
and Cervical Artery Dissection in Patients
with Neck Pain or Headache:
A Retrospective Cohort Study

The lead author is from the University Hospitals Cleveland Medical Center, Cleveland, OH. This study was funded by the US National Institutes of Health.

The objective of this study was to assess if adults experiencing new neck pain/headache had a significant increased risk for cervical artery dissection (CeAD) within 30 days following spinal manipulative therapy (SMT) compared to matched ibuprofen-prescribed controls.

The authors note that “there is no known link between ibuprofen and CeAD.” Consequently, ibuprofen prescription served as an active comparator, as a proxy for a clinical encounter wherein a patient sought evaluation for neck pain or headache. The authors matched 431,492 patients in each cohort (total of 862,984 patients). In this large study, the authors found:

• When a cervical artery dissection is attributed to spinal manipulation and chiropractic care, it may in fact be protopathic bias. This means that a spontaneous cervical artery dissection may give the patient neck pain and/or headache, and the patient seeks chiropractic care. The chiropractor did not cause the dissection. The chiropractic adjustment did not help the dissection, but it did not worsen the dissection. The dissection progressed to a stroke as it would have done even in the absence of chiropractic care.
• Only about 56% of cervical artery dissections result in stroke.
• The symptoms of cervical artery dissection following cervical spinal manipulation may be delayed for up to two weeks.
• Rarely the symptoms of cervical artery dissection following cervical spinal manipulation may be delayed for 4 four weeks.
• In the 30 days following initial neck pain/headache symptoms, the incidence of cervical artery dissection was lower in those receiving chiropractic manipulation compared to those who took ibuprofen.

The authors state:

“Among adults with new neck pain or headache, we found no increased cervical artery dissection risk within 30 days following chiropractor-administered SMT compared to receiving ibuprofen in an outpatient setting.”

“In clinical terms, these findings indicate no evidence of a meaningful increase in cervical artery dissection risk following SMT compared with ibuprofen.”

“Our findings are consistent with the hypothesis that adults presenting with new neck pain or headache may have a transiently elevated baseline risk of cervical artery dissection irrespective of treatment.”

“This study found no evidence of an increased risk of cervical artery dissection after chiropractor-administered cervical SMT compared with ibuprofen prescription in adults seeking care for new episodes of neck pain or headache.”

“This retrospective cohort study of 862,984 adults seeking care for a new episode of neck pain or headache found no evidence of an increased risk of CeAD within 30 days following chiropractor-administered cervical SMT compared with ibuprofen prescription.”

In support of their findings, the authors note:

• Studies in 2011, 2020, and 2022 “found no changes in carotid or vertebral arterial blood flow following cervical SMT in healthy volunteers or individuals with chronic nonspecific neck pain.”
• A 2023 cadaver study “found that the vertebral artery elongates without stretch during SMT.”
• “Our findings are consistent with two large studies that implemented both case-crossover and case-control analyses among patients presenting with neck pain or headache and found no significant association between SMT and CeAD.”

The safety of chiropractic spinal manipulation, especially as related to cervical artery dissection, continues to be well documented in the literature.

REFERENCES

1. Haldeman S; Modern Developments in the Principles and Practice of Chiropractic; Appleton-Century-Crofts; 1980.
2. Kirkaldy-Willis WH; Managing Low Back Pain; Second Edition; Churchill Livingston; 1988.
3. Kim S, Kim G, Kim H, Park J, Lee J, and nine more; Safety of Chuna Manipulation Therapy in 289,953 Patients with Musculoskeletal Disorders: A Retrospective Study; Healthcare; February 2, 2022; Vol. 10; No. 2; Article 294.
4. Chu E, Trager RJ, Lee L, Niazi IK; A Retrospective Analysis of the Incidence of Severe Adverse Events Among Recipients of Chiropractic Spinal Manipulative Therapy; Scientific Reports; January 23, 2023; Vol. 13; No. 1; Article 1254.
5. Cassidy JD, Boyle E, Côté P, Hogg-Johnson S, Bondy SJ, Haldeman, S; Risk of Carotid Stroke after Chiropractic Care: A Population-Based Case-Crossover Study; Journal of Stroke and Cerebrovascular Diseases; April 2017; Vol. 26; No. 4; pp. pp 842–850.
6. Haldeman S, Carey P, Townsend M, Papadopoulos C; Arterial Dissections Following Cervical Manipulation: The Chiropractic Experience; Canadian Medical Association Journal; October 2, 2001; Vol. 165; No. 7; pp. 905-906.
7. Mayer-Suess L, Frank F, Toll T, Boehme C, Gizewski ER, Ratzinger G, Broessner G, Stefan Kiechl S, Knoflach M; Head/Neck Pain Characteristics After Spontaneous Cervical Artery Dissection in the Acute Phase and on a Long Run; Cephalalgia; March 18, 2022; Vol. 42; No. 9; pp. 872–878.
8. Jacobs W, Wright DS, Pohlman K, Rosenbaum R, Hutten BA, Scholten-Peeters G, Haldeman S, Ket J, Rubinstein SM; Risk Factors for Cervical Artery Dissection: A Systematic Review with Meta-Analysis; Stroke & Vascular Neurology; June 29, 2026; Vol. 11; No. 3; pp. 275-285.
9. Trager RJ, Baumann AN, Labak CM, Lewis KL, Perez JA, Goertz CM, Schuster A; Association Between Spinal Manipulative Therapy and Cervical Artery Dissection in Patients with Neck Pain or Headache: A Retrospective Cohort Study; Chiropractic & Manual Therapies; September 14, 2026; Vol. 34; NO. 1; Article 53.

“Authored by Dan Murphy, D.C. Published by ChiroTrust® – This publication is not meant to offer treatment advice or protocols. Cited material is not necessarily the opinion of the author or publisher.”