A biomechanical study to compare spinal movement in a healthy volunteer during extrication between 'chain cabling' and 'roof off' methods of extrication.

INTRODUCTION: Following a motor vehicle collision some patients will remain trapped. Traditional extrication methods are time consuming and focus on movement minimisation and mitigation. 'Chain cabling' is an alternative method of extrication used in some countries. The optimal extrication strategy and the effect of extrication methods on spinal movement is unknown. This study compares 'chain cabling' to the established roof removal method of extrication on spinal movement. METHODS: Biomechanical data were collected using Inertial Measurement Units on a single healthy volunteer during multiple experiments. The extrication types examined were chain cabling and roof removal. Measurements were recorded at the cervical and lumbar spine, and in the anteroposterior (AP) and lateral (LR) planes. Total movement (travel), maximal movement, mean, standard deviation and confidence intervals are reported. RESULTS: Eight experiments were performed using each technique. The smallest mean overall movements were recorded during roof-off extrication (cervical spine 0.6 mm for AP and LR, lumbar spine 3.9 mm AP and 0.3 mm LR). The largest overall mean movements were seen with chain cabling extrication (cervical spine AP 5.3 mm. LR 6.1 mm and lumbar spine 6.8 mm AP and 6.3 mm LR). CONCLUSION: In this study of a healthy volunteer, roof-off extrication was associated with less movement than chain cabling. The movement associated with chain cabling extrication was similar to that previously collected for other extrication types.

Assessing spinal movement during four extrication methods: a biomechanical study using healthy volunteers.

BACKGROUND: Motor vehicle collisions are a common cause of death and serious injury. Many casualties will remain in their vehicle following a collision. Trapped patients have more injuries and are more likely to die than their untrapped counterparts. Current extrication methods are time consuming and have a focus on movement minimisation and mitigation. The optimal extrication strategy and the effect this extrication method has on spinal movement is unknown. The aim of this study was to evaluate the movement at the cervical and lumbar spine for four commonly utilised extrication techniques. METHODS: Biomechanical data was collected using inertial Measurement Units on 6 healthy volunteers. The extrication types examined were: roof removal, b-post rip, rapid removal and self-extrication. Measurements were recorded at the cervical and lumbar spine, and in the anteroposterior (AP) and lateral (LAT) planes. Total movement (travel), maximal movement, mean, standard deviation and confidence intervals are reported for each extrication type. RESULTS: Data from a total of 230 extrications were collected for analysis. The smallest maximal and total movement (travel) were seen when the volunteer self-extricated (AP max = 2.6 mm, travel 4.9 mm). The largest maximal movement and travel were seen in rapid extrication extricated (AP max = 6.21 mm, travel 20.51 mm). The differences between self-extrication and all other methods were significant (p < 0.001), small non-significant differences existed between roof removal, b-post rip and rapid removal. Self-extrication was significantly quicker than the other extrication methods (mean 6.4 s). CONCLUSIONS: In healthy volunteers, self-extrication is associated with the smallest spinal movement and the fastest time to complete extrication. Rapid, B-post rip and roof off extrication types are all associated with similar movements and time to extrication in prepared vehicles.