The anterior talofibular ligament(ATFL) is the most commonly injured part of the ankle. Thus by adding support and forces acting on the ATFL, testing the angle of ankle inversion is possible; according to previous research a subtalar angle greater than 25 degrees can cause injury. By using a simulation based program such as OpenSim, I should accurately be able to find an effective apparatus to prevent ankle injuries based on placing forces at certain point on the ankle to help prevent injury and keeping the subtalar angle under 25 degrees from a drop landing.