A Study of Lumbar Disc Injury under Typical Frontal Impact Load

Although the number of seriously injured cases of frontal impact has been sharply decreased, the spine injury especially the lumber injury is still at a high level, thereby resulting in serious consequences. This paper is aimed to investigate the lumber injury mechanism in terms of the extension, compression, flexion and rotation loads during the frontal crash using the newly established lumbar model, especially to study the injury mechanism in the lumber disc on a microscale. A new detailed model for the lumbar was used, and the micro index of stress and strain was then investigated to analyze the injury mechanism of the lumber disc in the regulation frontal crash. The complex load can be divided into several representable load patterns. Four representative loads were used to reflect the loads in real accident. At last, the correlation of load types and the micro distribution was discussed to describe the injury mechanism. The results show that the disc will have the greatest stress when the loads applied on the sample. The strain in the disc is several times larger than that on the spine, which indicates the disc is the crucial part when considering the spine injury in the frontal crash. Each load poses its unique strain/stress response on the disc. The annulus fibrosus of the disc is dangerous under all loads, though the nucleus pulposus of the disc is safe during the impacts. Results in this study can provide a reference to the spine used in the study of spine cord injury