Here is a study that in my opinion discusses many aspects to helping and understanding patients from trauma. This impact is similar to a rear end collision. This study discuses how the neck moves in a unnatural position (S shaped cervical curve) , how spinal cord injuries happen from a abnormal movement and how these injuries may not be detected on some imaging (why we may have to order more than 1 image to help our patients get a appropriate diagnosis and treatment plan from us), and the authors used a DMX, digital motion Xray to evaluate movement. I mention this because many insurance companies will argue that DMX is not commonly used. The authors did this test to show what happens in a MVC with airbag deployment hitting the face.
Here are some points the authors make: “This study revealed that direct backward impact applied to the face caused not only an extension motion of the cervical spine but also a flexion motion of the upper segments. Consequently, the cervical spine had an S shaped curvature with upper cervical spine flexion and lower cervical spine extension.”
“Regarding the difference in cervical spine alignment, 3 subjects with kyphosis had similar retraction-like motion to those with lordosis. However, for the forehead load, their upper cervical spine flexion was higher than that of the other subjects, while for the maxilla load, their upper and middle cervical spine flexion was less. Because the sample size was small, these conclusions have no statistical significance. However, theses results seem to suggest that curvature of the cervical spine influences the patterns of the cervical spine motion. Regardless of the impact location and cervical spine” Many studies show how abnormal cervical alignment influences movement.
The authors obviously could not impact the live specimens spine as much as the force created by a MVC or fall in fear of severly hurting the subjects. However. look what the authors conclude : “Regardless of the impact location and cervical spine alignment, the retraction-like motion was observed in all subjects. In an actual frontal car collision or falling accident, most likely the victim is being forced forward with a flexion motion before he/she receives a blow to the face, causing the upper cervical spine to be flexed more than it was in our experiments. We speculate that retraction-like motions observed in this experiment are the main causes of 2 common types of the cervical spine injuries: odontoid fracture and spinal cord injury without radiographic abnormality.” Abnormal mechanics during a impact can harm the spinal cord!
Authors Conclusion: “We hypothesize that direct face impact, commonly thought to cause an extension motion of the cervical spine, actually causes a flexion motion of the head and upper cervical spine, and it is this retraction motion, not an extension motion, that results in neck injuries.”
I feel we need to understand the complexities of these injuries but we can apply this to help so many more people!!
SPINE Volume 31, Number 8, pp 903–908 ©2006, Neck Injury Mechanisms During Direct Face Impact Makoto Fukushima, MD,* Koji Kaneoka, MD,* Koshiro Ono, DEng,† Masataka Sakane, MD,* Sadayuki Ujihashi, DEng,‡ and Naoyuki Ochiai, MD*