Use of Force and Restraint Principles
Lawful, necessary, proportionate, reported
Force is justified only when it serves a lawful purpose - self-defence, defence of another, defence of property, or effecting a lawful arrest or detention - and is reasonable in the circumstances. Reasonableness is judged on what you knew and perceived at the time, not with hindsight, but proportionality matters: the force must match the risk you faced, and it must stop when the risk stops.
Canadian use-of-force training uses a framework in which situational factors (number of subjects, weapons, time and distance, environment, your own capabilities, prior knowledge) shape your assessment of the subject's behaviour, which drives the option chosen: presence, communication, empty-hand control, intermediate weapons (baton, and any other weapon you are specifically authorized and trained to carry), or lethal force. The continuum is not a ladder. If behaviour justifies a higher option immediately, you may go there; when it drops, you must step down.
Restraint. Handcuffs are a use of force, not equipment for convenience. Use them to control someone lawfully arrested or detained who poses a risk; double-lock them, check fit and circulation, and monitor continuously. Positional asphyxia is the classic failure: once control is achieved, get weight off the back, neck, and chest, move the person to a recovery position, and watch breathing. Agitation, profuse sweating, incoherence, and sudden calm are medical red flags - call EMS; do not diagnose.
Baton: an intermediate weapon aimed at large muscle groups and limbs; avoid the head, neck, spine, and groin, and be able to justify each strike individually.
Traps: continuing force after resistance ends; handcuffing as punishment; treating 'subject is compliant' as 'subject is safe'; writing a report that says force was used without describing each application, its duration, target, and effect.
Rule of thumb: when the resistance stops, the force stops - and the clock on your report starts.