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

Background 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. Objective 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. Methods A crew of two paramedics and four firefighter 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. Results Control measurements were taken from the patient during self-extrication and movement was recorded of 4.194 degrees left of midline (LOM) to 2.408 degrees right of midline (ROM) resulting in a total movement of 6.602 degrees. The least deviation recorded during equipment aided extrication was movement of 3.365 degrees LOM and 8.352 degrees ROM resulting in a total movement of 11.717 degrees. The most deviation recorded during equipment aided extrication was movement of 1.588 degrees LOM and 24.498 degrees ROM resulting in a total movement of 26.086 degrees. Conclusions 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.