A multimodal approach for assessing the risk of cervical spine injury in low-speed rear-end collisions: kinematic and clinical responses.

PURPOSE: While advancements in vehicle safety have reduced injury severity in low-speed collisions, concerns about excessive treatment costs and the social implications of minor collisions persist. Cervical spine injuries, in particular, remain challenging to assess despite minimal vehicle damage. This study aimed to establish objective criteria for evaluating cervical spine injury risk in low-speed rear-end collisions and determine whether such injuries occur at impact velocities up to 8 km/h.

METHODS

Sixteen volunteers underwent controlled rear-end collisions using passenger vehicles and bumper cars at impact velocities ranging from 1.54 to 8.86 km/h. Kinematic parameters-including velocity change (ΔV), peak acceleration, and neck injury criteria (NIC)-were recorded. Cervical MRI scans were obtained pre- and post-collision, while electromyography (EMG) and nerve conduction studies (NCS) assessed neuromuscular function. Pain questionnaires were administered immediately after the test and 1 week later.

RESULTS

Impact velocity, offset percentage, and collision type significantly influenced acceleration forces and NIC values, with passenger vehicle collisions generating higher forces than bumper car collisions. Post-collision MRI scans showed no structural cervical spine damage, and no EMG or NCS abnormalities were detected. While 58.3% of participants reported immediate post-collision pain, this decreased to 25% within a week, primarily affecting the cervical spine and lower back.

CONCLUSION

The risk of cervical spine injury in low-speed rear-end collisions (ΔV≤8 km/h) appears minimal, with no significant structural or neuromuscular abnormalities observed. Further research is needed to assess long-term effects and improve occupant comfort.