Asymmetric Stability Margin of Postural Response to Perturbation in Unilateral Transtibial Amputees

Show full item record

Please use this identifier to cite or link to this item: http://hdl.handle.net/1853/14746

Title: Asymmetric Stability Margin of Postural Response to Perturbation in Unilateral Transtibial Amputees
Author: Tsai, Yi-Ying
Abstract: Falling is an important clinical problem in amputee population. In unilateral transtibial amputees, increased postural sway in quiet standing and asymmetric EMG reactions in anticipatory postural adjustments to rapid arm raises have been done previously. The goal of this study is to quantify directional deficits in postural control in individuals with unilateral transtibial amputation. We used the concept of stability margin, which is the difference of peak center of pressure (COP) and center of mass (COM) displacement, to characterize direction stability in response to multiple directions of support-surface perturbations in the horizontal plane. METHODS: Three subjects with unilateral, traumatic, transtibial amputation and three able-bodied subjects as a control group were recruited. Subjects were instructed to stand quietly with their arms crossed on the perturbation platform and were presented with a randomized set of support surface perturbation in the horizontal plane. We collected five replicates of each of the 8 perturbation direction (0º, 45º, 90º, 135º, 180º, 225º, 270º, 315º). Kinematic, kinetic and EMG data were recorded. RESULTS: Surprisingly, the stability margin in anterioposterior and mediolateral directions in amputee group was not significantly different from controls. However, stability margin was significantly reduced in the diagonal directions when the amputated side was loaded (45° and 315° perturbations, p <0.05). CONCLUSIONS: Our results show that the stability margin in amputees is reduced in diagonal directions where the amputated side in loaded and the intact side is unloaded.
Description: Presented at a Special Seminar: MSPO Student Presentations on April 18, 2007 at the Coon Building, Room 115 Runtime: 19:17 - Video of Presentation Runtime: 00:04 - Trial 27 Runtime: 00:04 - Trial 39 Runtime: 00:04 - Trial 43
Type: Masters Project
Video
URI: http://hdl.handle.net/1853/14746
Date: 2007-04-18
Contributor: Georgia Institute of Technology. School of Applied Physiology
Publisher: Georgia Institute of Technology
Subject: Directional deficits
Falling
Postural sway
Reduced diagonal stability
Stability margin
Unilateral transtibial amputations
Advisor: Research Mentor: Lena H. Ting ; Advisor: Robert Kistenberg

All materials in SMARTech are protected under U.S. Copyright Law and all rights are reserved, unless otherwise specifically indicated on or in the materials.

Files in this item

Files Size Format View Description
presentation_tsai.mp4 48.91Mb MPEG-4 video View/ Open Video of Presentation
presentation_tsai.pdf 385.9Kb PDF View/ Open Power Point Presentation
handout.pdf 20.48Kb PDF View/ Open Handout
trial27.mp4 451.8Kb MPEG-4 video View/ Open Video of Trial 27
trial39.mp4 345.2Kb MPEG-4 video View/ Open Video of Trial 39
trial43.mp4 437.8Kb MPEG-4 video View/ Open Video of Trial 43
presentation_tsai_streaming.html 929bytes HTML View/ Open Streaming Video of Presentation
trial27_streaming.html 919bytes HTML View/ Open Streaming Video of Trial 27
trial39_streaming.html 919bytes HTML View/ Open Streaming Video of Trial 39
trial43_streaming.html 919bytes HTML View/ Open Streaming Video of Trial 43

This item appears in the following Collection(s)

Show full item record