Characteristics of PMHS Lumbar Motion Segments in Lateral Shear

The purpose of this study was to determine the characteristics of eighteen lumbar spine motion segments subjected to lateral shear forces under quasi-static (0.5 mm/s) and dynamic (500 mm/s) test conditions. The quasi-static test was also performed on the lumbar spine of a side impact anthropomorphic test device, the EuroSID-2 (ES-2). In the quasi-static tests, the maximum force before disc-endplate separation in the PMHS lumbar motion segments was 1850 ± 612 N, while the average linear stiffness of PMHS lumbar motion segments was 323 ± 126 N/mm. There was a statistically significant difference between the quasi-static (1850 ± 612 N) and dynamic (2616 ± 1151 N) maximum shear forces. The ES-2 lumbar spine (149 N/mm) was more compliant than the PMHS lumbar segments under the quasi-static test condition.