Validation of Tracking Dynamic Motion of the Ankle in Vivo
The purpose of this pilot study is to determine the accuracy of our volumetric model-based tracking technique to measure the in vivo motion of the ankle. Subjects for this study will consist of patients undergoing ankle surgery. During surgery, three small (1.0 mm diameter) tantalum beads will be placed in the tibia, fibula, talus and calcaneus. Approximately six months after surgery, a stereoradiographic system will collect high-speed radiographs of the operated and healthy ankle during various dynamic movement trials.
Principal Investigator: William Anderst, PhD and MaCalus Hogan, MD
Biplane radiographs of the foot and ankle during walking. Radiographs were collected at 100 images per second with 1 ms exposure time during overground walking. The model-based tracking process was used to track the motion of the tibia, fibula, talus and calcaneus from just prior to foot strike through the late push-off phase of gait.
Foot Plantar Pressures
The purpose of this study is to establish the natural side-to-side variability in foot loading in healthy individuals. and to determine if there are any differences in plantar pressure during treadmill versus overground walking. Although considerable research has been done comparing treadmill and overground gait in terms of joint kinematics and kinetics there is a paucity of data comparing foot loading patterns during treadmill and overground gait. Specifically, pressure under uninjured (“control”) feet is often compared to contralateral injured or surgically repaired feet for clinical evaluation.
Principal Investigator: MaCalus Hogan, MD, MS and William Anderst, PhD
Finite Element Model of the Ankle Joint
The purpose of this study is to develop a subject-specific finite element model of the tibiotalar joint to estimate contact pressure during gait. Finite element models of the ankle have been developed to examine in vitro loads at the tibiotalar joint during simulated standing in healthy and injured ankle joints. However, there are currently no in vivo studies of tibiotalar cartilage pressure during dynamic loading activities such as gait.
Principal Investigator: Bradley Campbell, PhD and William Anderst, PhD