Master of Science in Biological and Agricultural Engineering (MSBAE)


Biological and Agricultural Engineering

Document Type



The purpose of this project is to modify, validate, and gather preliminary clinical data on a novel ankle stiffness device that measures stiffness (torque / degree) and range of motion (ROM) of the ankle joint complex (AJC). The initial device was designed by a mechanical engineering design group at Louisiana State University in 2006, but had not been tested on human participants. Clinical evaluation of the ankle joint is important in patients afflicted with diabetes mellitus, Hansen’s disease, or peripheral neuropathies. The combination of peripheral neuropathies, decreased ankle range of motion, and increased stiffness pose a threat to these patients, and often plays a significant role in ulcerations and other pathologies of the foot. Using instrumentation, the data gathered from the device was validated to ensure accurate ankle parameter measurements. Testing of normal participants and participants with one previously injured ankle was then undertaken. Injured participants had normal sensation with one non-injured and one previously injured ankle and were used as their own control. Testing (typically 45-60 minutes) involved securing the participant’s ankle in the device, and measuring the torque as the ankle was passively rotated through the participant’s ROM, in both plantarflexion and dorsiflexion. Torque versus Range of Motion (TROM) curves were mathematically fit using regression analysis and analyzed to assess differences between injured and uninjured ankles. TROM curves were compared based on the average torque, angular velocity, dorsiflexion and plantarflexion slopes, and the hysteresis in the functional range of motion of ankle rotation. Significant difference, at a α = 0.05, was not found in these parameters across all ankles including healthy, injured (normal), and injured. However, significance was found between the unstretched and stretched treatment across the all groups at an α = 0.05 in average torque (unstreched: 148.13 ± 4.78 in*lb and stretched: 143.73 ± 4.78 in*lb, p = 0.0442) and dorsiflexion slope (unstreched: 3.18 ± 0.21 in*lb/deg and stretched: 2.70 ± 0.21 in*lb/deg, p = 0.0006). The result of this study validate that the device can determine biomechanical properties of the AJC, and could be utilized in a clinical environment.



Document Availability at the Time of Submission

Secure the entire work for patent and/or proprietary purposes for a period of one year. Student has submitted appropriate documentation which states: During this period the copyright owner also agrees not to exercise her/his ownership rights, including public use in works, without prior authorization from LSU. At the end of the one year period, either we or LSU may request an automatic extension for one additional year. At the end of the one year secure period (or its extension, if such is requested), the work will be released for access worldwide.

Committee Chair

Monroe, W. Todd

Included in

Engineering Commons