# Development of a Foot-Ankle Prosthesis to Improve Physical Therapy Outcomes

> **NIH VA I01** · MINNEAPOLIS VA  MEDICAL CENTER · 2020 · —

## Abstract

Reduced balance and balance confidence are common impairments among individuals with lower-limb
amputations. It is therefore important to develop and evaluate therapeutic interventions designed to improve
balance and balance confidence in this population. Conventional approaches to balance training currently
involve weight-shifting and stepping exercises that challenge single-limb stance and balance recovery. During
this time, new prosthesis users typically wear a flexible prosthetic foot-ankle mechanism designed for walking.
Although individuals with lower-limb amputations eventually adapt to the sudden balance requirements of their
new prosthesis, their confidence is likely influenced by a persistent threat of falling.
The long-term goal of this work is to compare a conventional approach of balance training with a modified
program in which the balance requirements of the prosthesis user are gradually increased. To vary the balance
requirements of the prosthesis user, a novel foot-ankle device will be developed at the Minneapolis VA Health
Care System (MVAHCS), which will allow therapists to gradually adjust the stability of the foot-ankle system as
patients learn to safely transfer weight over their prosthesis. This new device will enable physical therapists to
maximize stability at the beginning of physical therapy, thereby allowing patients to weight shift with a highly
stable system. As the patient's confidence increases, therapists will be able to gradually decrease the stability
of the device.
The primary goals of our development work will be to develop a prosthetic foot-ankle system that is durable
and that allows for easy adjustments (i.e., a system that requires little extra training or tools to accomplish).
Consideration will also be given to a method of tracking these adjustments so that therapists can document the
patient's progress during the course of physical therapy. Following each design iteration, we will mechanically
test the foot-ankle system for static proof, ultimate strength, and cyclic fatigue according to the ISO 10328
standard for lower-limb prosthetic components. We will then perform human subject testing to assess the
standing and walking performance of the device and obtain feedback to guide design modifications. Using
three-dimensional motion analysis and a clinical balance assessment system, we will collect kinematic, kinetic,
and postural stability data on a group of experienced prosthesis users (n=8) while they stand and walk with the
proposed foot-ankle system. The goal of this testing will be to ensure biomimetic function of the ankle and
verify expected kinematic changes with regard to its range-of-motion settings. We will also conduct human
subject testing on a group of new amputees (n=4) undergoing physical therapy at the MVAHCS, which will
provide an opportunity for the prosthetists and physical therapists involved in the study to gain experience with
the device. In parallel with our development efforts, we...

## Key facts

- **NIH application ID:** 10070517
- **Project number:** 5I01RX002267-03
- **Recipient organization:** MINNEAPOLIS VA  MEDICAL CENTER
- **Principal Investigator:** Andrew H. Hansen
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2017-12-01 → 2021-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10070517

## Citation

> US National Institutes of Health, RePORTER application 10070517, Development of a Foot-Ankle Prosthesis to Improve Physical Therapy Outcomes (5I01RX002267-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10070517. Licensed CC0.

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