The effect of single-handed cricoid pressure on cervical spine movement after applying manual in-line stabilisation...

Six adult cadavers had 40 N cricoid pressure applied using a cricoid 'yoke' whilst maintaining manual in-line stabilisation of the cervical spine. No other spinal supports were used. Lateral radiographs were taken before and after applying pressure to the cricoid cartilage and the degree of cervical spine movement accurately determined. The median vertical displacements measured from the body of C5 and two other reference points (A and B) on the cervical spine were 0.5 mm (range 0-1.5 mm) and 0.5 mm (range 0-3 mm), respectively. There was no disruption to the lines formed by the anterior or posterior borders of the cervical bodies. We have been unable to demonstrate that single-handed cricoid pressure causes clinically significant displacement of the cervical spine in a cadaver model. This conflicts with previous studies.