Type of Submission
Poster
Keywords
Gait, varus, knee load, static model, bowlegged, femur
Abstract
The purpose of this study was to take known experimental loads throughout normal gait and to find the corresponding loading at the knee for both normal gait and abnormal gait. Abnormal gait was defined as a person with varus, i.e. “bowleggedness”, or a person who had an external rotation of the femur (or the inability to internally rotate the femur) which caused an indirect varus in the forward positions of gait. This problem was approached by imposing static equilibrium on the femur. This allowed the loads at the knee to be calculated from the loading at the hip. In order to find the forces for abnormal gait, the angular movement of the femur from the normal location was determined. Then, the forces applied to the femoral head were rotated in relation to the femur in order to simulate where the force would be applied when the bone was in the new position for abnormal gait. Once the forces at the hip were rotated about the femoral head, the loading at the knee for each of the cases was determined. The code written allows a user to define the amount of varus and external rotation. The user can then see a graphical representation of the loading through the gait cycle on the knee. Additionally, the maximum loading cases of gait at the knee are recorded and shown. The key thing noted in the results was an increase in adduction moment for the abnormal gait cases in comparison to the normal gait. Understanding knee loading for abnormal gait will help design engineers understand the range of loading conditions of knee implants in-vivo.
Faculty Sponsor or Advisor’s Name
Dr. Timothy Norman
Campus Venue
Stevens Student Center
Location
Cedarville, OH
Start Date
4-16-2014 11:00 AM
End Date
4-16-2014 2:00 PM
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Determining Knee Loading for Abnormal Gait
Cedarville, OH
The purpose of this study was to take known experimental loads throughout normal gait and to find the corresponding loading at the knee for both normal gait and abnormal gait. Abnormal gait was defined as a person with varus, i.e. “bowleggedness”, or a person who had an external rotation of the femur (or the inability to internally rotate the femur) which caused an indirect varus in the forward positions of gait. This problem was approached by imposing static equilibrium on the femur. This allowed the loads at the knee to be calculated from the loading at the hip. In order to find the forces for abnormal gait, the angular movement of the femur from the normal location was determined. Then, the forces applied to the femoral head were rotated in relation to the femur in order to simulate where the force would be applied when the bone was in the new position for abnormal gait. Once the forces at the hip were rotated about the femoral head, the loading at the knee for each of the cases was determined. The code written allows a user to define the amount of varus and external rotation. The user can then see a graphical representation of the loading through the gait cycle on the knee. Additionally, the maximum loading cases of gait at the knee are recorded and shown. The key thing noted in the results was an increase in adduction moment for the abnormal gait cases in comparison to the normal gait. Understanding knee loading for abnormal gait will help design engineers understand the range of loading conditions of knee implants in-vivo.
