The human respiratory system stipulates that the chest has constant movements that allow the normal pulmonary ventilation. If the latter is impeded in its movement here that we find ourselves in the presence of positional asphyxia. The oxygen that circulates in the blood is lost gradually doing that carbon dioxide takes its place causing feelings of illness and in extreme cases, after long periods of duress, even the death of the individual. In Bdsm is recommended, especially to those who uses or practices Bondage Kimbaku, always keep this in mind Asthe can 'damage not indifferent. One of the practices that provide the increased risk of positional asphyxia is the crucifixion.