Biomechanical investigation of lower limb injuries in military scenarios: using Finite element modeling approach

Abstract

The injuries to foot-ankle complex is common due to different type of activities , such as falls from a height especially in parachute landing where frequently damage is caused to this region. Ankle injuries results into long-term impairment due to such injuries as chance of poor vascularity increases, which affects working ability. The current research requires creation of finite element model of foot, based upon computer tomography (CT) images with an objective to develop a CAD and to predict the stress distribution within foot bones due to landing. Image processing technique was used to develop model’s geometry whereas anatomical images were provided by the Radiology Department, PIMS. Meshing scheme was established through mesh sensitivity test and the finite element method is then utilized to analyze response of the foot bones. FE model incorporated realistic component structures and material properties of bones, ligaments and tendon. As the first part of study required model validated, so the stress was assessed for controlled balance standing conditions. Results were validated according to mentioned readings.The validated model was then enacted to predict the localized stress distribution in foot bones during landing with different foot postures: Flat foot, plantar flexion and dorsiflexion, under velocity based impact loading. The test results showed maximum stress in ankle region bones and joints in all three mentioned postures of foot during landing while Plantar flexed foot absorbed maximum reaction forces during landing and high stress value was observed for each foot bone in this case.