Ejection from military aircraft exerts substantial loads on the lumbar spine. Fractures remain common, although the overall survivability of the event has considerably increased over recent decades. The present study was performed to develop and validate a biomechanically accurate experimental model for the high vertical acceleration loading to the lumbar spine that occurs during the catapult phase of aircraft ejection.
View Article and Find Full Text PDFIt is well known that rotational loading is responsible for a spectrum of diffuse brain injuries spanning from concussion to diffuse axonal trauma. Many experimental studies have been performed to understand the pathological and biomechanical factors associated with diffuse brain injuries. Finite element models have also been developed to correlate experimental findings with intrinsic variables such as strain.
View Article and Find Full Text PDFDiffuse brain injury (DBI) commonly results from blunt impact followed by sudden head rotation, wherein severity is a function of rotational kinematics. A noninvasive in vivo rat model was designed to further investigate this relationship. Due to brain mass differences between rats and humans, rotational acceleration magnitude indicative of rat DBI ( approximately 350 krad/s(2)) has been estimated as approximately 60 times greater than that of human DBI ( approximately 6 krad/s(2)).
View Article and Find Full Text PDFA new experimental model was developed to induce diffuse brain injury (DBI) in rats through pure coronal plane angular acceleration. An impactor was propelled down a guide tube toward the lateral extension of the helmet fixture. Upon impactor-helmet contact, helmet and head were constrained to rotate in the coronal plane.
View Article and Find Full Text PDFThe relationship between diffuse brain injury (DBI) occurrence and impact biomechanics is well documented. Previous studies attempted to develop injury thresholds based on various biomechanical parameters and have demonstrated inconsistent results. The spectral nature of DBI requires robust metrics capable of predicting injury occurrence and severity.
View Article and Find Full Text PDFCommonly considered a continuum of injuries, diffuse brain injury (DBI) ranges from mild concussion to severe diffuse axonal injury. The lower end of the spectrum is generally referred to as mild traumatic brain injury (MTBI). More severe forms of DBI have garnered extensive experimentation while these milder cases are considerably less explored.
View Article and Find Full Text PDFDue to the frequency of closed head injuries and cost of treatment, there is great interest in the mechanical parameters involved in provoking the injury. A new device has been developed to produce closed head injury due to impact-induced angular acceleration in the rat. A 488-gram mass was propelled down a 2-meter drop tube by springs at a velocity of 21 mph (9.
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