Related Experiment Video
Updated: Aug 14, 2026

A Test Bed to Examine Helmet Fit and Retention and Biomechanical Measures of Head and Neck Injury in Simulated Impact
Published on: September 21, 2017
Cervical misalignment in motorcyclists in relation to new helmet removal recommendations shown with augmented reality
Ana Nicolás Carrillo1,2, Javier Ruiz Casquet1,3, Juan José Hernández Morante1
1New Technologies for Health Research Group, UCAM Universidad Católica de Murcia, Spain.
Objective:
The aim of this study is to determine the best technique and position for helmet removal in injured motorcyclists by comparing cervical misalignment produced in the supine position and prone position.
Method:
Comparative cross-sectional clinical simulation study to quantify CM using biomechanical analysis with the use of inertial systems. The main variable was determined for the flexion-extension motion. The extraction was tested for both positions (prone position and supine position), which were repeated 3 times for each of the 30 volunteers included, and the movement from the initial neutral position was also determined, resulting in a total of 270 biomechanical studies.
Results:
A flexion was observed when moving the patient from the neutral position to the SP, due to the size of the helmet, of 1.29° ± 5.12°. Helmet removal in the supine position resulted in an average flexion-extension range of 17.51° ± 6.49°, while the same extraction in prone position recorded an average range of 10.82° ± 8.05°. For the main variable, statistically significant differences were found when comparing prone position and supine position (p = 0.0087).
Conclusions:
The main conclusion of the study is that the helmet removal should be done in the position in which we find the patient, whether in prone position or supine position. Additionally, the new technique described for the prone position causes less movement of the cervical spine than the usual supine position.
Related Concept Videos
Collar Bearings
Transmission Shafts: Problem Solving
Next, use bending moment diagrams for the shaft to...

