Determination of Human Vertebral Force Response to +Gz Impact from exterior accelerations

Modeling and simulation of complex biomechanical systems can be developed to provide insight into the loading of otherwise immeasurable conditions. Ejection from an aircraft is a highly dynamic event with a risk of injury during the entire sequence. During one of the phases of ejection, spinal compression injury is a definite possibility and test manikins are used to asses this risk. However, care must be taken before accepting the relationship between the measured load in a manikin an the assumed load in a human. Human impact tests are often conducted to asses the biodynamics at a sub-injury level. Correlating these human biodynamics with manikin dynamics, can provide this relationship. To complete this correlation, modeling and simulation can be used to augment the available human test data so that the parameters of interest can be calculated. To this end, a rigid body dynamics model was constructed to represent a vertical impact for both humans and manikins. This model was then validated through human impact test data and a method was developed to demonstrate how to build this correlative relationship. This method is a very robust and direct way to calculate the internal lumbar load for human testing.