This thesis focuses on the injuries of the lumbar spine due to high rate loading, using both cadaveric experiments and numerical modelling. Insurgent warfare has been characterised by the use of improvised explosive devices, often targeting military personnel inside vehicles. Those incidents are associated with spinal injuries of poor clinical outcome. Currently, spinal injury tolerance levels do not exist for the loading seen by blast casualties, and the biomechanics of the lumbar spine are not understood under impact loading. Experimental and numerical models were developed to investigate the response of single segments and bi-segments of the lumbar spine under impact loading conditions. A novel methodology for controlling posture and ensuring axial loading during experiments was developed. A single segment numerical model was developed using the finite element method;​ the load transmission through the segment and its stress distributions were analysed. A bi-segment numerical model was also developed and three different positions on the sagittal plane were simulated;​ flexed (10 ͦ), neutral (0 ͦ) and extended (-5 ͦ). Differences between postures were predicted and areas prone to injury were identified. The neutral posture was found to be the most severe for the same loading conditions. Injurious impact tests of bisegment cadaveric specimens were performed for the aforementioned postures, and the neutral posture was found to sustain injuries associated with the poorest outcome compared to the flexed or extended specimens. The methodologies and technologies developed in this thesis can be used further to look into the injury biomechanics aspects of the lumbar spine and used as a test-bed for assessing current and develop new mitigation strategies. Immediate next steps would be to include the rest of the lumbar spine in the numerical model and then the pelvis so that the loading pathway from the seat through to the spine can be quantified.