Sellick maneuver consists of elevating the patient's chin (without displacing the cervical spine) and then pushing the Cricoid cartilage posteriorly to close the esophagus.
A bimanual technique was later described by Crowley and Gieseckel. in which the left hand is placed under the patient's neck to stabilize it. The cricoid is stabilized between the thumb and third finger while the index finger pushes down.
Sellick's original paper described ventilation during Cricoid pressure in patients with full stomachs.