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An Article from our blog posts


Positional  Asphyxiation and  the  Arresting  Officer

By Gary Foo; Police Use of Force Instructor and Tactical Paramedic


"Positional Asphyxiation" (PA) is a serious life threatening condition that all Use of Force

practitioners should be made aware of.  Fundamentally, is can occur when a subject is

pinned down in such a way that it becomes difficult to breathe and may be exacerbated 

when certain other health and disease elements are present. They may even state they

cannot breathe during the arrest or when lying in certain prone positions. 

This that can reduce the likelihood of PA, may be when pinning the subject face downs to

handcuff - that the transition from takedown to side control to handcuff is does smoothly

and expeditiously with a brief 'pin' (knee) behind the shoulder blade  / scapular instead of

the neck, when possible.  This isn't always easy especially when larger or strong actively combative subjects resist arrest. However, that would be the preferred procedure and first choice. But PA can also occur other ways and without any human providing additional compression, such as an arrested subject handcuffed in such as way that briefing is difficult and they lie or fall unconsciously in an awkward position. This is not common and a number of additional factors, comorbidities, external elements are usually at play. 

It’s not easy being a police officer. However like firefighters there seems no shortage of applicants to join the ranks of dedicated men and women in service. They want to become one of those special people who “Serve and Protect” as the saying goes.

Like all positions of power and privilege, there also comes great responsibility.  And not many like a police officer where a judgment call or split second decision may result in the loss of life.

It is important that Police, Security, Military, EMS / Medics and other law enforcement personnel understand the existence of Positional Asphyxiation (PA) and recognize and even anticipate it and the factors which cause it. Failing to do so may render a routine arrest that escalates into physical control of an individual, causing a death or serious harm when using such force.  

“PA is Asphyxia that occurs from positioning of the body (i.e., hyperflexion of the neck, prone positioning) that interferes with the airway or bellows function of the respiratory muscles. Also called postural asphyxia” 

Dr Brian Bledsoe 2003

Defining Positional Asphyxiation (PA)

Although it’s been defined for some years now and I wrote about it in several books and texts many years ago, it is still  relatively unknown and poorly understood.  “Positional Asphyxia” (also sometimes called “Postural Asphyxia” or “Restraint Asphyxia.”) is often defined as obstruction of breathing as a result of some form of restraint technique being applied. (It does happen in other situations but in the context of an arrest it usually occurs when the person’s body position interferes with their ability to breath often with other contributing factors.  


It can happen unexpectedly although there does seem to be common contributing factors.


In the context of an arrest, the subject is usually facedown (or ‘prone’) and is unable to breath easily in that position. It is exacerbated when there is a heavy weight (like several officers who are pressing) on the subjects back.  It can also happen when supine (face up) with weight on their stomach area – especially if the subject has a large (beer belly) abdomen. This scenario can happen easily with arresting officers trying to control a subject on the ground especially if more officers or people come and add ‘weight’ to gain control of the arrested subject. 


Hyperflexion of the neck and arching of the back are other affecting considerations. This can be further intensified if the subject is choked and / or when the subject’s back becomes very arched such as when handcuffed and tied to the feet (also known as ‘hog tying’).


Causative Factors in Positional Asphyxiation (PA) 

Some research suggests that certain commonalities are present with Positional Asphyxiation and there are also usually underlying health issues, such as obesity, cardiomyopathy (enlarged heart) or other cardiac issues as well as some level of systemic compromise in the body.  


For example, especially in those with big stomachs, there may be pressure on the diaphragm into the thoracic cavity impairing a normal or comfortable breathing position. With difficulty breathing and then holding/blowing one’s breath and whilst being compressed there is also the physiological impact of a mechanism called the “Valsalva maneuver.” 


This amongst other many things may impair normal breathing and possibly agitate a normal sinus rhythm (or heartbeat) if sustained along with other factors. And if (a normal) carotid sinus rhythm is affected through something like a neck restraint, by massaging the vagus nerve, several other factors may come into play that ultimately could negatively impact the subject – especially the older they are.  From syncope (unconsciousness) to plaque thrombus (blockage) to even death, there are a multitude of possible implications from neck locks, pins and chokes.  


If this is not recognized, death can occur from asphyxia or suffocation and other factors such as cardiac arrest may be suspected.  Obviously we know that any body position that interferes with a person’s ability to breath can cause death. In fact we should all know that it can take as little as three minutes without air to cause serious damage to the body and brain and may result in death. Sometimes it may occur sooner than that.  


Also caution should be exercised by anyone applying any neck restraints (and its different versions including the carotid neck restraint, the ‘sleeper’ hold, the lateral vascular neck restraint (LVNR), the martial arts ‘blood chokes; and ‘air chokes’ etc). especially in individuals over 40 years of age or so.  


Whilst these may be safety applied in the right conditions by trained or expert technicians they should not be ‘first choice’ when other options exist unless high level of resistance incurred with commensurate threat to officer and public safety.

Justified force


I should emphasize at this point that we are not discussing the justification for the use of force at this point. It is axiomatic to assume that this is an unquestionably lawful arrest and the use of force being applied is justified.  


I do not need to remind you that Officers have a tough job under difficult circumstances and are often outnumbered, outweighed, and have split seconds to chose a response to an aggressive and threatening level of assault or resistance. 

Some Officers have had to discharge their firearm or use one of their other “less-than-lethal” levels of force available to them whilst a violent or violent sociopath is intent on killing an innocent and defenseless member of public or police and anyone who stands in their way. 


So, we do know that we would have to be controlling a seriously dangerous offender, often with serious threat to the officer, to justify a lethal use of force. In writing this I am assuming that the use of force is justified and the arrest obviously lawful. 

Considerations to using force


We know that “Use of Force” is an umbrella subject which deals with the operational tactics, strategies and legal justification to control subjects who have to be brought to justice. 


Sometimes subjects are behaving in a dangerous, assaultive or resistant manner and usually it is the police or other person in authority who is effecting the ‘use of force’ in response to that subject.  Police have a duty to bring those offenders to justice whilst trying to keep themselves and others free from harm.


These days with so many camera phones and CCTV cameras the police and other public servants are being scrutinized, often unfairly, by a legion of public ‘armchair quarterbacks’ who were not there, did not see what happened first but are now able to dissect a situation at their leisure, that took a split second decision to come to.  


However there are some situations where this also keeps the officers honest and the community aware of those rare times when officers do slide off  the rails and use compromising methods to control subjects, sometimes without justification.


Regular Training Required

It is incumbent on Police departments and other law enforcement and security agencies to teach appropriate Use of Force, and the awareness of positional asphyxiation, and how to potentially recover from it if possible and suspected. There should also be regular and practical sessions in approved subject control methods always starting with effective Tactical Communications.  


And I am not solely placing responsibility on the departments but I also believe like any profession that officers are responsible for a certain level of self-directed learning and when that information is known to conduct themselves within standards and the law.  


Factors to be aware of in PA (Positional Asphyxiation) 

Therefore, we need to be aware of some of the risk factors in recognizing the possibility of positional asphyxia. These are not 100% and may occur without these present but seem to increase the risk profile and may include:

  •  Older and less healthy individuals

  •  Large bellied individuals

  •  Awkward sustained body positions which compromise breathing

  •  Prone (subject face down) ground pin with sustained heavy weight on rear torso

  •  Supine (face up) ground pin with sustained heavy weight on their chest / abdomen 

  •  The subject telling you he/she cannot breathe

  •  Gasping or other sounds indicating airway compromise

  •  Increasing panic, prolonged resistance clearly struggling to breath

  •  Sudden limp, still or tranquil state (especially after resisting)

  •  Cyanosed areas (grey/blue lips, hands, face) due to lack of oxygen (cyanosis)

  •  Neck veins plump and more evident 

  •  Known or suspected history of related health problems (including heart, respiratory and metabolic such as diabetes)

  •  Known or suspected abuse of drugs (i.e. cocaine) and / or alcohol

  •  Known or suspected condition of ‘excited delirium’ or agitated and escalated.


Again I emphasize that if you choose the appropriate approach in your response to the subject and are justified in choosing a force control option and escalate or de-escalate accordingly as you lose or gain compliance respectively, then you have to make that decision as you know appropriate at the time. 


However, in some cases there may be other options or considerations and if you do see, for example, the subject during arrest say “I can’t breathe” and go limp then you need to recognize options and departments need to train accordingly.  It’s a tough call and no one knows more than we do how difficult it can be out there.


What you should do if you suspect Positional Asphyxiation

Should you suspect PA a factor in your subject, you may need to rapidly weigh up the threat to public safety and subject control versus subject welfare and change from arrest mode to treatment mode, if possible. 


By that I mean, if he is not stabbing you with a knife or you are a small female officer in a dark roadside who just managed to get the upper hand with a large violent drunk quarterback, you might consider switching to checking for vital signs and exploring repositioning the handcuffs and even calling for advanced medical care whilst you check for a patent airway and initiate chest compressions. 



Positional Asphyxiation in custody is still a real risk and we need to be aware that it exists.


There are many tactical options at this stage and several medical protocols possible.  It is important that we know that Positional Asphyxiation exists, what may increase its likelihood of occurring and what to do if it does.     


Whenever possible it is paramount that officers try to deescalate a confrontation by using good effective Tactical Communications and when physical force is necessary be aware to the possibility of “Positional Asphyxiation.”  With some fighting and aggressive subject you may still have limited options but it is important you do what you can IF you can.



About Gary Foo

Gary is a noted authority on Use of Force and has experience as a Police Officer in the UK and Canada. He is a Tactical Medic / TCCC / Paramedic trainer and is a published author


He is a United Nations Coordinator and Disaster Risk Reduction and Emergency Response Advisor and qualified Rescue Technician and Disaster Management / SAR (Search and Rescue) Instructor and has deployed all over the world including Haiti, Sri-Lanka, Middle East, South-East Asia, Afghan-Pakistan border, Bolivia, The Philippines, China and others.  

He specialised in Use of Force and Armed / Tactical Policing and is an instructor trainer in that regard. He has worked in Close Protection / Bodyguarding internationally protecting Royal Families, Celebrities, HNW Individuals and Political / Corporate Leaders.  He is a black belt martial arts instructor and use of force advisor. 

He can be contacted through this website


and the UN recognized INSARAG Team


  • Fire/Emergency Medical Services Department Operational Considerations and Guide for Active Shooter and Mass Casualty Incidents  September 2013  FEMA, US

  • Bulletin National Law Enforcement Technology Center Positional Asphyxia—Sudden Death June 1995 U.S. Department of Justice Office of Justice Programs National Institute of Justice

  • (Major portions of this bulletin are drawn from a report prepared by the International Association of Chiefs of Police for the National Institute of Justice (NIJ), based on research conducted by Dr. Charles S. Petty, Professor of Forensic Pathology, University of Texas, and Dr. Edward T. McDonough, Deputy Chief Medical Examiner, State of Connecticut, and reviewed by the Less-Than-Lethal Liability Task Group.) 

  • Issues in Patient Restraint - April 2003 by Dr. Bryan Bledsoe, DO, FACEP The George Washington University Medical Center (Presentation)

  • Security Officers | Positional / Restraint Asphyxia - April 2012 – Victoria Police

  • Use of Force Positional Asphyxia – July 2006 Her Majesty’s Prison service 

  • Restraint Asphyxia – Silent Killer, Part ONE – 2004 - Charly D. Miller (Presentation)

  • Tactical Communications – 1993, 2002, 2012 – Gary Foo 

  • Tactical Handcuffing Manual  2012 – 3rd Edition – Gary Foo

  • Use of Force and Positional Asphyxiation – [Not published / In Process] – By Gary Foo


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