Training and stage CPR thumb|US Navy sailors practice chest compressions on mannequins. It is dangerous to perform CPR on a person who is breathing normally. These chest compressions create significant local blunt trauma, risking bruising or fracture of the sternum or ribs. If a patient is not breathing, these risks still exist but are dwarfed by the immediate threat to life. For this reason, training is always done with a mannequin, such as the well-known Resusci Anne model.
Training and stage CPR thumb|US Navy sailors practice chest compressions on mannequins. It is dangerous to perform CPR on a person who is breathin.g normally. These chest compressions create significant local blunt trauma, risking bruising or fracture of the sternum or ribs If a patient is not breathing, these risks still exist but are dwarfed by the immediate threat to life. For this reason, training is always done with a mannequin, such as the well-known Resusci Anne model.