Optimal Selection of Prosthetic Knee and Foot Combination for Improving Walking and Standing Performance in Transfemoral Prosthesis Users
Abstract
Numerous studies involving human subjects testing, mechanical characterizations, and computer simulations have been conducted to compare different types of prosthetic components in order to better understand their impact on prosthesis users’ activities of daily living. However, to date there have been no systematic investigations to determine how to best combine a prosthetic knee and foot for improving walking and standing performance in transfemoral prosthesis users. This proposed study will evaluate both swing and stance phase functions of transfemoral prostheses by combining mechanical prosthetic knee and foot components that individually offer distinct and desirable advantages. The goal is to identify those prosthetic knee and foot combinations that impart greater benefits to the user than others. This investigation will be limited to mechanical prosthetic components and will not include microprocessor-controlled devices. However, the principles that are explored can be universally applied to increase clinical understanding about fitting both mechanical and microprocessor-controlled prosthetic components. The purpose of this study is to systematically compare different combinations of mechanical prosthetic knee joint and foot-ankle components to determine how walking and standing performance are affected in transfemoral prosthesis users. This project will involve a collaborative effort between Northwestern University and the Jesse Brown VA Medical Center. For the first aim, we will perform computer simulations of the transfemoral prosthesis configurations with the different combinations of prosthetic knee and ankle components to determine how swing phase foot clearance is affected and stance phase stability of the prosthetic knee joint is influenced. For the second aim, we will perform quantitative gait analyses on subjects walking on level ground, stairs and slopes with polycentric and single-axis knees, and hydraulic and solid foot-ankle components. Finally, for the third aim, the standing balance of subjects will be evaluated using a series of tests that measure upright balance during quiet standing and stability following balance perturbation. This project will require 4 years to complete. This work is directly applicable to the Veteran Health Administration’s Patient Care Mission because the results may improve the gait and quality of life of Veterans with lower limb amputations. The Vital and Health Statistics National Health Interview Survey indicate that as of 1996 there were 1,285,000 persons in the U.S. with some type of major upper- or lower-extremity amputation, putting the incidence of major absence of extremities at approximately 4.9 cases per 1,000 persons. The current U.S. population is estimated to be 321,400,000 people, so the number of persons with major amputation of the extremities is approximately 1,574,860. Statistics from the Veterans Health Administration (VHA) reported that between 1989 and 1998, there were 60,324 new lower limb amputations performed on 44,007 Veterans, of which 29.4% were at transfemoral level. Most importantly, 94% of these new amputations were performed on older Veterans between the ages of 45 and 84. Based upon these figures, we estimate that there are approximately 463,000 individuals in the U.S. (a rate of about 1:694 persons) with transfemoral amputation. Therefore, there are roughly 12,400 unilateral transfemoral amputees within a 60-mile radius of Chicago (based upon a population of roughly 8.6 million people). Assuming similar age demographics with the current population of amputee Veterans, this emphasizes the strong relevance and potentially high impact of this research on the vast majority of current VHA amputee patients. Recruitment for this study will occur primarily through Jesse Brown VA Medical Center, the Edward Hines, Jr. VA Hospital, the Northwestern University Prosthetics-Orthotics Center, and the Shirley Ryan AbilityLab, but we will a
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 19, 2019
- Source ID
- W81XWH1910447
Entities
People
- Steven A Gard
Organizations
- Northwestern University
- United States Army