==== Front
Innov Aging
Innov Aging
innovateage
Innovation in Aging
2399-5300 Oxford University Press US 

10.1093/geroni/igaa057.684
igaa057.684
Abstracts
Session 2899 (Poster)
Cardiovascular Health and Disease
AcademicSubjects/SOC02600
Investigation of Roll-Over Characteristics in Healthy Old Individuals and Patients With Peripheral Artery Disease
Myers Sara 1 Bapat Ganesh 1 Johanning Jason 2 Pipinos Iraklis 2 1 
University of Nebraska at Omaha, Omaha, Nebraska, United States
2 
University of Nebraska Medical Center, Omaha, Nebraska, United States
2020 
16 12 2020 
16 12 2020 
4 Suppl 1 Program Abstracts from The GSA 2020 Annual Scientific Meeting “Turning 75: Why Age Matters”212 212
© The Author(s) 2020. Published by Oxford University Press on behalf of The Gerontological Society of America.2020This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.Abstract
Atherosclerotic blockages in the leg arteries, cause leg pain with ambulation (called claudication), impair gait and substantially reduce the walking ability of patients with peripheral artery disease (PAD). Ankle-foot orthoses are being developed and applied so patients can walk more and with less pain. Roll-over shape (ROS) is a potential design objective for such assistive devices. In the proposed work, we study roll-over characteristics in patients with PAD and healthy older subjects. Gait data of ten healthy older individuals (Age: 72.8 ± 5.5 years) and twenty patients with PAD (Age: 64.1 ± 6.6 years) were collected at self-selected walking speed. In patients with PAD, gait data were collected before the onset of pain and after claudication pain was induced. To generate ROS, the center of pressure data was transformed to the shank-based coordinate system and circular arcs were fit using an optimization program in MATLAB. Independent t-tests with Bonferroni corrections were used to separately compare roll-over radius differences (p<0.05) between healthy older to both walking conditions in patients with PAD. The mean roll-over radius was not significantly different between healthy older vs PAD pain-free (p=0.468) or PAD pain-induced (p=0.289) walking conditions. Our results indicate invariance of ROS radius in patients with PAD, which is consistent with previous literature showing general invariance of ROS in healthy young individuals. Previous biomechanical studies show gait kinematics and kinetics are more affected by PAD than by age. Future studies should focus on the potential adaptive mechanisms in patients with PAD achieving invariant ROS.