# Exoskeleton footwear to improve walking performance and subject-reported preference.

> **NIH VA I01** · OMAHA VA  MEDICAL CENTER · 2021 · —

## Abstract

The long term goal of this project is to improve the quality of life of patients with peripheral artery
disease (PAD) using assistive exoskeletons. PAD is a manifestation of systemic atherosclerosis that
significantly reduces blood flow to the lower extremities. Veterans with PAD undergo angioplasty,
proximal bypass, and distal bypass procedures at rates 10 times higher than the general US male population.
Reduced blood flow leads to pain during walking known as claudication. Claudication pain that results
from PAD causes patients to walk less and slower, and lose independence compared with their healthy
counterparts. Our research has identified functional limitations in the walking patterns of claudicating patients,
the most prominent and consistent of which is a deficit of the psterior calf muscles, the ankle plantarflexors, to
generate healthy ankle toruqe and power during walking. A properly designed exoskeleton will allow patients
with PAD to walk longer without pain or walk the distance needed for completing daily activities with less stress
to the affected leg. Before EF can be implemented in patients with PAD, the design must be improved to
increase walking performance and actual patient use. As a first step we propose to determine the effect of EF
on walking performance, focusing on the how EF contributes to changes in the biological ankle torque and
power, energy cost, and calf muscle oxygenation. We will test healthy older adults to ensure and confirm
comfort, decrease risk of injury to the foot and calf, and cultivate high potential for device adoption in patients
with PAD. The EF will then be evaluated in patients with PAD. Healthy older individuals are selected for this
initial phase because like patients with PAD, they produce less push-off torque and power during walking
compared with healthy young; making them an appropriate model for PAD limitations. Our specific aims are:
Aim 1: To determine the levels of EF assistance force level which produce better walking
performance in older subjects.
Aim 2: To determine the levels of EF assistance force which produce better subject-reported preference
in older subjects.
Aim 3: To determine the effect of EF assistance levels on walking performance and subject-reported
preference in patients with PAD. Aims 1 and 2 results will guide the assistance levels tested in this aim.
50 healthy older adults for Aims 1 and 2, and 25 patients with PAD for Aim 3 will be recruited from the Nebraska
and Western Iowa Veterans Affairs’ Medical Center and surrounding Omaha community. Aim 1 will test
seven conditions, including five levels of EF assistance, the EF with no spring and one normal walking
condition. Lower extremity torque and power will be measured using gait biomechanics on the
treadmill for three minutes per condition. Muscle oxygenation will be measured with near infrared spectroscopy
of the calf muscles. A metabolic cart will be used to measure energy cost. Aim 2 will thoroughly assess
subjec...

## Key facts

- **NIH application ID:** 10144012
- **Project number:** 5I01RX003266-02
- **Recipient organization:** OMAHA VA  MEDICAL CENTER
- **Principal Investigator:** Sara A Myers
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2021
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2020-04-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10144012

## Citation

> US National Institutes of Health, RePORTER application 10144012, Exoskeleton footwear to improve walking performance and subject-reported preference. (5I01RX003266-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10144012. Licensed CC0.

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