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 Scandinavian 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.
What We Did
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.
What We Found
Eight experiments were performed using each technique. The smallest mean overall movements were recorded during roof-off extrication (cervical spine 0.6mm for AP and LR, lumbar spine 3.9mm AP and 0.3 mm LR). The largest overall mean movements were seen with chain cabling extrication (cervical spine AP 5.3mm. LR 6.1mm and lumbar spine 6.8mm AP and 6.3mm LR).
Cervical AP Maximal movement
* Error bars indicate 95% confidence intervals
Chain cabling extrication compared to other extrication types
Error bars indicate 95% Confidence Intervals
What This Means
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.
- Self-extrication is associated with smaller movements at the cervical and lumbar spine than other extrication types
- Extrication types that are not self-extrication appear to be similar in movement generation at the cervical and lumbar spine
- There is a disconnect between the extrication techniques that are considered to reduce movement and their performance in this regard
Authors
Tim Nutbeam, Rob Fenwick, Barbara May, Willlem Stassen, Jason E Smith, Jono Bowdler, Lee Wallis and James Shippen