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Top medical experts explore safety of vascular neck restraints. Will their findings matter?

To better inform policies regarding the training and use of VNRs by law enforcement, emergency medicine doctors published their latest research


“It’s important to note that VNR is distinctly different from a chokehold,” said William P. Bozeman, M.D., professor of emergency medicine at Wake Forest University School of Medicine and emergency medicine physician at Atrium Health Wake Forest Baptist. “A chokehold is a form of neck compression that can restrict breathing, but VNR does not impair respiration.”

Photo/Wake Forest University School of Medicine

Originally published on the Force Science Institute website. Republished here with permission.

The full study is available here: Safety of Vascular Neck Restraint Applied by Law Enforcement Officers

By Lewis “Von” Kliem, MCJ, JD, LLM

In 2021 federal politicians concluded that both chokeholds and carotid restraints – also known as vascular neck restraints (VNR) – were inherently dangerous and had “too often led to tragedy.” With this pronouncement, federal law enforcement officers were prohibited from using either a chokehold or carotid restraint unless deadly force was authorized.

Reportedly, to incentivize state and local governments to similarly ban “chokeholds,” the U.S. Department of Justice proposed that federal law enforcement grants (e.g., “Byrne” and COPS grants) be limited to jurisdictions in which chokeholds and carotid holds were prohibited by law.

When assessing relative risk, use-of-force experts question whether chokeholds and carotid restraints should be lumped together. Choke holds are intended to restrict breathing and are reasonably likely to damage airway structures as a result. At the same time, a “properly performed VNR does not apply pressure to the anterior neck, airway, or trachea, and does not impair respiration.” [1] Dr. Bill Lewinski, Executive Director at Force Science, adds, “There is important research that indicates the vascular restriction stemming from a properly performed carotid restraint does not impair the vertebral blood flow that supports the critical, life-sustaining areas of the brain.” [2]

It follows that many agencies have limited chokeholds to deadly force encounters, with some states banning them altogether. On the other hand, vascular neck restraints have enjoyed a reputation for being highly effective and reducing injuries to both officers and suspects. That said, civic leaders and communities might reasonably expect that police use-of-force practices, including neck restraints, be founded on more than just reputation, anecdotes and myths. They expect to see the evidence.

Beyond Reputation, Anecdotes and Myths

To better inform policy decisions regarding the training and use of VNRs by law enforcement, a group of highly-credentialed emergency medicine doctors published their latest research titled, “Safety of Vascular Neck Restraint applied by law enforcement officers.” [3]

Joined by top criminologists and sociologists, medical researchers reviewed VNR applications by law enforcement in both field and training environments. Here is what the evidence showed.

Over an 11-year period, three North American law enforcement agencies collectively applied VNRs over 940 times while arresting combative or resistive subjects. [4] An additional 230 police uses of the VNRs were identified in a separate 2021 report. [5] Combined, these 1,174 instances of law enforcement’s use of VNR found no significant injuries (i.e., moderate or severe injuries) and no deaths. Further, the risk of minor injuries was low.

On the training side, researchers reported that approximately 85,918 officers/trainees received initial and/or refresher training. During the training, over 14,000 students received at least one VNR with full pressure, and 71,835 received multiple partial pressure applications.

For field uses, the success of a VNR was defined by its effectiveness in allowing apprehension of a resisting or combative subject. Of the agencies reviewed, the aggregate success rate was 92%. Notably, one agency reported that 76% of their effective (i.e., allowed apprehension) VNR applications did not result in the suspect losing consciousness.

Effective but How Safe?

Researchers involved in the VNR study were interested in more than just tactical effectiveness. Hoping to inform both police policy and evidence-based recommendations for medical providers, researchers set out to determine the rate of medical complications after a VNR use.

Of the 944 VNR field uses by law enforcement, researchers observed that there were no fatalities and no significant (moderate or severe) injuries related to VNR uses. Of the nine subjects with reported injuries following the use of a VNR, only one injury was a direct result of the VNR, and it was mild (i.e., neck soreness). The remaining injuries were also evaluated as mild and resulted from other causes (e.g., grappling, canine deployment, conducted electrical weapon use).

In the training arena, of the estimated 85,918 students, no fatalities or significant injuries were reported. There were 76 mild injuries reported, most (61%) related to grappling, while only 29 (38%) of the injuries were due to the VNR application (e.g., neck and shoulder soreness, dizziness, headaches). [6]

Rare but Serious Complications

The large sample in this study allowed the researchers to conclude that the VNR was a highly-effective and safe option for law enforcement. Even the risk of minor injury was low. Still, researchers noted, “These findings do not exclude the possibility of a rare serious complication or guarantee safety if the technique is not applied correctly.”

Dr. Lewinski echoed the researchers’ warning, “The safety of the VNR is directly tied to its proper application, and training is key. Not only do we expect officers to know how to apply a proper VNR against a dynamic and resisting suspect, we expect them to know which people to avoid. That may mean officers will avoid using the VNR against very young, the elderly, and those people with obvious head or neck injuries. We would also highlight the risk associated with a VNR against people with features commonly associated with Down syndrome.”

Beyond Safety and Effectiveness

As police reform activists and academics advocate for evidence-based policing, we see a renewed emphasis on pushing research into practice. That said, as with any measure of police effectiveness, the desired social outcome of the reviewer may determine whether an evidence-based practice will be embraced or rejected.

Unfortunately, myths and misinformation surrounding the VNR (and in-custody deaths generally) will continue to drive policy decisions. In other words, political and community support for any police practice may involve more than just safety and effectiveness.

Consider, if traditional law and order interests (e.g., officer safety, public safety, law enforcement) are priorities, then intelligence-led policing, problem-oriented policing, and effective and safe force options may prove most useful in accomplishing those goals.

However, where civic leaders prioritize other political or social interests, evidence-based recommendations may be less about effectiveness and safety and more about restoring a perception of legitimacy, accountability and community involvement.

In announcing the federal limitation on chokeholds, the U.S. Attorney General explained, “The Department of Justice today announced written department-wide policies explicitly prohibiting the use of ‘chokeholds’ and ‘carotid restraints’ unless deadly force is authorized….”

The Attorney General continued, “Building trust and confidence between law enforcement and the public we serve is central to our mission at the Justice Department. The limitations implemented today on the use of ‘chokeholds,’ [and] ‘carotid restraints’ […], are among the important steps the department is taking to improve law enforcement safety and accountability.”

With law enforcement (and citizen) safety among the goals of the Department of Justice, then the Safety of Vascular Neck Restraint applied by law enforcement officers will be of great interest in future policy development.

Still, there are challenges for even the most thoughtful civic leaders. If constituents refuse to distinguish the chokehold from the VNR or choose to view chokehold – and, by extension, the VNR – as symbols of enduring police racism and abuse, the call to ban all neck manipulations will likely continue.

One local NAACP president opined, “A chokehold by another fancy name is still a chokehold. Whatever the name may be, it is really another attempt by an officer to put his arm around someone’s neck,” “When we see someone with their arms wrapped around someone’s neck, that is a chokehold.” [7]

Researchers succinctly identified the irony, “The absence of fatalities or significant injuries demonstrated by our data, combined with a high success rate and lower overall subject injury rate compared to other force options reported in another recent study, suggest that these bans may be unnecessary when the VNR technique is executed by well-trained LEOs.”

The researchers continued, “Further, banning a safe and effective force option may be counterproductive by forcing [law enforcement officers] to utilize other force options with higher risks of injury.”

Additional articles related to Vascular Neck Restraint can be found at:


1. Bozeman WP, et al. Safety of Vascular Neck Restraint applied by law enforcement officers. (Oct. 9, 2022.) Journal of Forensic and Legal Medicine, 9(92):102446.

2. See Samuel J. Stellpflug, Thomas R. Menton, Jesse J. Corry & Aaron B. Schneir. (2020.) There is more to the mechanism of unconsciousness from vascular neck restraint than simply carotid compression. International Journal of Neuroscience, 130(1):103-106.

3. William P. Bozeman (Wake Forest University, Emergency Medicine), Gary M. Vilke (University of California, San Diego, Emergency Medicine), Christine Hall (University of British Columbia, Emergency Medicine), Nicholas P. Petit (Wake Forest University, Emergency Medicine), Diane L. Miller (University of North Carolina, Emergency Medicine), Kristy K. Ford (Wake Forest University, Emergency Medicine), Brian Hiestand (Wake Forest University, Emergency Medicine), and Jason P. Stopyr (Wake Forest University, Emergency Medicine).

4. The three law enforcement agencies participating in the study were the San Diego Police Department, the North Carolina State Highway Patrol and the Royal Canadian Mounted Police.

5. Hickman MJ, Scales RM, Strote JM, Worrall JL. (2021.) Use of VNRs in law enforcement: A case study of Spokane, WA. Police Pract Res, 22(6):1668-1678.

6. Researchers reported that, “These VNR-related mild injuries included neck and shoulder soreness, sprain/strain, or swelling, dizziness or headache, and one case of hemotympanum. There were no cases of cervical fractures, vascular injuries or dissections, strokes, or other intracranial pathology identified.”

7. Police wrestle with definition of chokehold, Los Angeles Times (quoting Gerald Hankerson, president of the Seattle King County NAACP).

About the author

Lewis “Von” Kliem, MCJ, JD, LLM, has worked as a civilian police officer, attorney, educator and author. Von is the executive editor of Force Science News and co-owner of Von Kliem Consulting, LLC, where he trains and consults on constitutional policing, use of force analysis, crisis communications and trauma-informed interviewing.

The FSRC was launched in 2004 by Executive Director Bill Lewinski, PhD. -- a specialist in police psychology -- to conduct unique lethal-force experiments. The non-profit FSRC, based at Minnesota State University-Mankato, uses sophisticated time-and-motion measurements to document-for the first time-critical hidden truths about the physical and mental dynamics of life-threatening events, particularly officer-involved shootings. Its startling findings profoundly impact on officer training and safety and on the public’s naive perceptions.