Characterization of the transverse and spinous vertebral processes: fracture forces under quasi-static and dynamic loading - biomed 2010.

The purpose of this study was to investigate the response and failure properties of the transverse and spinous vertebral processes under cantilever bending. Twelve human third lumbar vertebrae (L3) were harvested from donors aged 56-79 years, and the processes were loaded in either dynamic (1000 mm/s) or quasi-static (1 mm/s) cantilever bending. All of the spinous processes were loaded dynamically, and transverse process loading was alternated between dynamic and quasi-static and between right and left. Peak forces measured for the transverse processes were 252 +/- 77 N and 234 +/- 50 N in the dynamic and quasi-static tests, respectively, which corresponded to lack of rate sensitivity in the transverse process peak force for the range of loading rates considered (p=0.6). Peak forces measured for the spinous processes were 1179.6 +/- 587.1 N, and both subject mass (p=0.038) and subject age (p=0.006) were found to be significant predictors of peak force.