This work aims to assess the protection provided by an airbag, a back protector and their combination under blunt back impacts which could cause thoracic and spinal trauma. Finite element modelling was used to simulate normal impacts to the HUMOS2 model at L1 level, one of the most vulnerable regions of the spine. Multiple impact conditions, based on the results of previous multibody accident simulations, were simulated on the human model by testing the protectors and reference simulations without any protection. The behaviour of airbag and back protector models was previously validated from drop impact experimental data. Impact force, intervertebral joint rotation from T1 to L5, organs internal energy and back compression were measured to estimate impact severity. Peak contact force mitigation is the main benefit of back protectors, especially for penetrant impacts. In addition to impact force and intervertebral rotation, the airbag decreases back compression and organ deformation due to its higher energy absorption capacity. Coupling the airbag with the back protector increases the effectiveness of the inflatable device by distributing the impact on a larger area of the bag providing the best protection for both flat and penetrant impact conditions.