OBJECTIVETo investigate the damage characteristics and biomechanical mechanisms of the thoracolumbar vertebral bursh fracture during the impact loading.

METHODSFrom September 2008 to October 2009, 10 fresh human thoracolumbar spine specimens were collected for experimental model and divided into two groups. Biomechanical static and dynamic impact strength test were performed respectively in two groups. The static and dynamic data from thoracolumbar vertebrae shock response in different loads were observated.

RESULTSThoracolumbar yield load was (5 280.00 +/- 354.2) N, yield displacement was (13.32 +/- 2.07) mm, the limit load was(6 590.00 +/- 249.20) N, ultimate displacement was (20.60 +/- 2.57) mm, load speed was 0.02 g, and the average limit load of dynamic mechanical properties of thoracic and lumbar vertebrae was (14 425.60 +/- 1101.52) N, the average reaction time load was (17.29 +/- 2.04) ms, the average of acceleration was (36.80 +/- 2.81) g, the dynamic displacement was (45.11 +/- 1.13) mm.

CONCLUSIONThoracolumbar vertebral burst fracture is a serious injury caused by the release of high-energy moment, the role of biomechanical forces are in a pattern of pulse change, thoracic and lumbar vertebrae present with the viscoelastic properties of biological materials.