This NLETC bulletin presents information relevant to positional asphyxia—i.e., death as a result of body position that interferes with one’s ability to breathe— as it occurs within a confrontational situation involving law enforcement officers. We offer this information to help officers recognize factors contributing to this phenomenon and, therefore, enable them to respond in a way that will ensure the subject’s safety and minimize risk of death:
As soon as the subject is handcuffed, get him off his stomach. Turn him on his side or place him in a seated position.
If he continues to struggle, do not sit on his back. Hold his legs down or wrap his legs with a strap.
Never tie the handcuffs to a leg or ankle restraint.
If required, get the suspect immediate medical attention.
Do not lay the person on his stomach during transport to a station house or hospital. Instead, place him in a seated position.
https://www.ncjrs.gov/pdffiles/posasph.pdf