Physical Intervention Knowledge
KNOWLEDGE-ONLY revision covering why PI is a last resort, risks, duty of care, communication, monitoring and post-incident actions. This section does NOT teach practical technique.
Practical training required
Practical Physical Intervention skills must be learned and assessed through appropriate face-to-face training with a qualified trainer. This online section is for knowledge revision only.
Physical Intervention as a Last Resort
PI is only used when other options have failed or are not available, and force must be reasonable and proportionate.
Key concepts
- Use of force in England and Wales must be reasonable in the circumstances (common law and, where relevant, statute).
- Verbal, environmental and tactical de-escalation should be tried first where possible.
- The lowest level of force capable of achieving a lawful objective should be used.
Ask: is intervention necessary, lawful, proportionate and the least intrusive option?
Retreat and reassess is an acceptable and often the right option.
Common misunderstandings
- 'They started it' does not automatically make any level of force lawful.
- Not intervening physically is often the correct decision.
Risks Associated with Restraint
The physical and medical risks that make restraint dangerous.
Key concepts
- Restraint carries a risk of positional asphyxia, cardiac events and other serious harm — even death.
- Risks are higher with people affected by alcohol, drugs, obesity, respiratory illness or acute mental distress.
- Restraint should be for the shortest time possible.
Any weight or pressure on the chest, back or neck significantly raises the risk of asphyxiation.
Remove restraint as soon as it is safe to do so and continuously monitor the person.
Common misunderstandings
- 'Compliant' does not mean 'safe' — someone can deteriorate rapidly during restraint.
- Restraint is never routine; each use carries risk.
Duty of Care
Legal and ethical duty owed to the person being restrained.
Key concepts
- You owe a duty of care to anyone in your custody or control, including someone being restrained.
- Duty of care includes their safety, medical needs and dignity.
- Failure of duty of care can result in criminal charges and civil claims.
Consider vulnerabilities (age, disability, pregnancy, mental health) before and during any intervention.
Never leave a restrained or recently restrained person unattended.
Common misunderstandings
- The person's behaviour does not extinguish the duty of care.
- Duty of care applies both during and after any intervention.
Communication During Intervention
Continuous, calm communication with the subject and the team.
Key concepts
- Explain what you are doing and why.
- Give clear, achievable instructions — one at a time.
- Continue to look for cues that de-escalation may now be possible.
Confirm the person can breathe and speak — 'Can you tell me your name?'
Announce when you are about to release the intervention.
Common misunderstandings
- Shouting during restraint often increases the person's fear response.
- Silence during restraint removes the opportunity to de-escalate.
Team Communication During Intervention
Coordinated team roles, watchers and safety leads.
Key concepts
- Nominate a lead communicator and a safety monitor for the subject.
- Colleagues should keep the space clear and watch for bystanders or additional threats.
- Use simple, agreed commands.
Rotate roles if the intervention is prolonged and additional staff are available.
Radio for medical support at the earliest sign of distress.
Common misunderstandings
- Everyone shouting instructions confuses the subject and the team.
- The person doing the restraint is not always the best communicator.
Monitoring a Restrained Person
Continuous observation of breathing, colour, consciousness and responsiveness.
Key concepts
- Observe airway, breathing and circulation continuously.
- Look for changes in colour (paleness, blueness around lips), sweating and consciousness.
- If any concern, release the restraint, put the person in a safer position and call for help.
If the person becomes unresponsive, treat it as a medical emergency and call 999 immediately.
Prepare to perform first aid, including CPR if trained.
Common misunderstandings
- 'They were talking a second ago' is not reassurance — deterioration can be sudden.
- Face-down restraint significantly increases risk and should be avoided or minimised.
Positional Asphyxia Awareness
The mechanism, warning signs and prevention of positional asphyxia.
Key concepts
- Positional asphyxia occurs when body position restricts breathing.
- Face-down positions, weight on the back, and pressure on the neck are high-risk.
- Signs include difficulty breathing, colour change, quietening, unresponsiveness.
Reposition the person to a safer position (e.g. seated or recovery) as soon as possible.
Do not sit, kneel or place body weight on the person's back, chest or neck.
Common misunderstandings
- A person who has 'gone quiet' has not calmed down — they may be in serious medical trouble.
- Being able to speak is not proof of being able to breathe adequately.
Recognising Signs of Distress
Physical and behavioural indicators of medical or psychological distress.
Key concepts
- Rapid, shallow or absent breathing, sweating, colour change or unresponsiveness are red flags.
- Verbal cues ("I can't breathe") must be taken seriously every time.
- Sudden calm following extreme agitation may indicate deterioration.
If in doubt, release, reposition and call 999.
Stay with the person and provide reassurance while help is on the way.
Common misunderstandings
- Distress is not always dramatic — subtle signs matter.
- Adrenaline can mask injury or illness in both subject and staff.
Medical Assistance
Requesting help and providing basic first aid within your training.
Key concepts
- Dial 999 for anything more than a minor injury or if you are unsure.
- Only provide first aid within the limits of your training.
- Communicate clearly with call handlers about location, condition and any restraint used.
Bring first aid equipment and any available defibrillator to the scene.
Support ambulance access and clear routes for the crew.
Common misunderstandings
- Waiting to see if someone recovers can waste critical time.
- Delaying the call because of paperwork is a serious safeguarding failure.
Post-Incident Actions, Reporting & Debrief
What to do after any physical intervention.
Key concepts
- Record the incident factually, chronologically and in detail.
- Include justification for the intervention and the least-force principle used.
- Notify management and, where required, the police.
Support colleagues involved and offer welfare check-ins.
Use the debrief to improve future practice, not to apportion blame informally.
Common misunderstandings
- Discussing accounts collectively before writing them can compromise evidence.
- 'Nothing happened' is rarely an accurate summary — record all interventions.