Biomechanical analysis of spinal immobilisation during prehospital extrication: a proof of concept study

In most countries, road traffic collisions (RTCs) are the main cause of cervical spine injuries. There are several techniques in use for spinal immobilisation during prehospital extrication; however, the evidence for these is currently poor.

The objective of this study is to establish which technique provides the minimal deviation of the cervical spine from the neutral inline position during the extrication of the RTC patient using biomechanical analysis techniques.

A crew of two paramedics and four fire-fighter first responders extricated a simulated patient from a prepared motor vehicle using nine different extrication techniques. The patient was marked with biomechanical sensors and relative movement between the sensors was captured via high speed infrared motion analysis cameras. A 3D mathematical model was developed from the recorded movement.

Control measurements were taken from the patient during self-extrication and movement was recorded of 4.194° left of midline (LOM) to 2.408° right of midline (ROM) resulting in a total movement of 6.602°. The least deviation recorded during equipment aided extrication was movement of 3.365° LOM and 8.352° ROM resulting in a total movement of 11.717°. The most deviation recorded during equipment aided extrication was movement of 1.588° LOM and 24.498° ROM resulting in a total movement of 26.086°.

Conventional extrication techniques record up to four times more cervical spine movement during extrication than controlled self-extrication. This proof of concept study demonstrates the need for further evaluation of current rescue techniques and the requirement to investigate the clinical and operational significance of such movement.