# Improving mobility in peripheral artery disease using an ankle foot orthosis

> **NIH NIH R01** · UNIVERSITY OF NEBRASKA OMAHA · 2020 · $408,149

## Abstract

Peripheral artery disease (PAD) is a manifestation of systemic atherosclerosis,
characterized by atherosclerotic blockages of the arteries supplying the legs.
Claudication, defined as walking induced gait dysfunction and muscle pain, is the most
common manifestation of PAD. Claudication affects 5% of Americans older than 55
years of age. Claudicating patients experience reduced mobility, reduced physical
functioning, poor health outcomes, and increased risk for falls. Research in our
laboratory has documented significant deficits in the ankle plantarflexors to generate
normal torque and power during walking. Further, affected legs of patients with PAD
demonstrate a muscle myopathy that prevents normal muscle function. While supervised
exercise is effective for increasing the distance patients with PAD can walk, it does not
generate ankle plantarflexor torque, or decrease stress on the leg muscles. An ankle-
foot orthosis (AFO) is a device made of carbon-composite material that can offset ankle
plantarflexor torque and power and decrease blood flow demand and muscular stress
during walking. The spring-like properties of carbon composite AFOs allow energy
storage at weight acceptance and return at the point of toe off. Our pilot work has shown
that walking with an AFO immediately increases the initial and absolute walking
distances in patients with PAD as much as pharmacotherapy for six months. This study
will determine whether an AFO improves walking performance in patients with PAD from
its first use. Additionally, the study will test walking performance after a three month AFO
intervention and will examine the feasibility of this AFO intervention. The central
hypothesis is that the AFO immediately improves walking performance by decreasing
the energy cost of walking. Walking performance improvement following the three-month
intervention is expected to be larger than that of first use due to improving the muscular
function of patients' affected legs. Detailed measures of mechanisms related with
walking performance, muscle contribution, physical activity, quality of life and how these
mechanisms change after wearing the AFO for three months will provide the evidence
required to implement an AFO therapy that will improve functional status and quality of
life in individuals with PAD.

## Key facts

- **NIH application ID:** 9976549
- **Project number:** 5R01HD090333-05
- **Recipient organization:** UNIVERSITY OF NEBRASKA OMAHA
- **Principal Investigator:** Sara A Myers
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $408,149
- **Award type:** 5
- **Project period:** 2016-09-23 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9976549

## Citation

> US National Institutes of Health, RePORTER application 9976549, Improving mobility in peripheral artery disease using an ankle foot orthosis (5R01HD090333-05). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9976549. Licensed CC0.

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