Tissue displacement and impact force are important contributors to outcome after spinal cord contusion injury

Spinal cord contusion injury in rodents is widely used as a model for spinal cord trauma in humans. Several biomechanical variables can influence injury outcome. In this work, we have assessed the influence of impact force and displacement of the spinal cord at the time of contusion injury on the severity of locomotor deficits and histopathological changes. Our work indicates that there is a linear relationship between force and tissue displacement, and that both these factors contribute to injury outcome. Furthermore, our work also suggests that setting narrow limits for the actual force applied (+/-5 kdyn) and tissue displacement (within a 200 microm range) will yield more consistent outcomes and provide greater sensitivity in detecting changes, regardless of the type of impactor device used.