Energy flow in the human head subjected to impact loading

Literature review has revealed that over a dozen of finite element models are worldwide available that may be employed to predict the stress or pressure levels inside a head subjected to impact. Based on the predicted stressed the likelihood of the human head injury is assessed in the same manner as we evaluate structural strength. This methodology, however, deviates from the practice in experimental studies of biomechanics. In the latter, energy or power is frequently employed. Structural Intensity (SI) is a vectored quantity indicating the direction and magnitude of power flow inside a dynamically loaded structure. In this paper, we apply SI to study biodynamic response of the human head subjected to impact loading. A finite element model of the head is built and it is validated with experimental results. The SI field inside the head model is computed for three cases: frontal, rear and side impacts. The results for the three cases have revealed that there exist power flow paths. Skull is in general good energy flow channel. The study has also revealed the high possibility of spinal cord injury due to wave motion inside the head.