# Robotic Knee Exoskeleton to Reduce Joint Loading and Improve Mobility in Veterans with Medial Compartment Knee Osteoarthritis

> **NIH VA I21** · VA PUGET SOUND HEALTHCARE SYSTEM · 2020 · —

## Abstract

Symptomatic knee osteoarthritis (OA) is a painful condition that reduces mobility, independence, and quality of
life for both men and women. About 10% of people aged over 55 years have painful disabling knee OA of
whom one quarter are severely disabled. Although a variety of factors influence the pathogenesis of OA,
medial compartment knee joint contact loading plays a significant role and importantly, is a modifiable risk
factor. Traditional knee unloader braces are a common conservative treatment strategy for those with medial
compartment knee OA. Unloader braces are designed to unload the medial compartment of the knee joint
thereby slowing disease progression, reducing pain, and improving joint function and mobility. Medial
compartment unloading provided by a brace abduction moment (BAM) counteracts the external knee
adduction moment (KAM). Unfortunately, traditional knee unloader braces have mixed efficacy and the limited
benefits (minimal reduction in pain and minor functional improvements) of wearing the brace do not often
outweigh the brace discomfort and hassle of use. One of the shortcomings of traditional knee unloader braces
is that the BAM must be manually set by the brace user through strapping and or condyle pad adjustment. This
results in infrequent adjustment which often causes an inappropriate BAM setting for a given activity, e.g.
strapping has loosened resulting in a BAM that doesn’t provide enough knee unloading during gait, or the
subject is at rest but the BAM remains high causing pressure and discomfort at the brace interface. Even
when walking BAM modulation within a step could be beneficial. In this scenario, BAM could be reduced during
swing phase but then return to a normal level during stance phase. For these reasons, we propose that a new
class of smart active braces that dynamically adapt the amount of unloading for a given individual and their
activity. This new class of braces has the potential to provide greater medial compartment knee unloading and
better pain relief while simultaneously being more comfortable. Therefore, the purpose of this research
study is to determine optimal BAM modulation profiles that provide better medial compartment knee
unloading, improve brace comfort and reduce knee pain as compared to conventional passive knee
unloader braces. To achieve our aims, we have developed an offboard robotic knee exoskeleton (RKE) to
serve as a laboratory tool to investigate the potential benefits of active braces with dynamic BAM modulation.
For this study, twenty participants will be recruited to walk on an instrumented treadmill while wearing the
(RKE). The participants will experience 56 different BAM modulation schemes as parameterized by the BAM
turn on time (Ton), turn off time (Toff) and peak Nm BAM level (Pk). Real-time data analysis will allow us to
immediately compare the efficacy of each BAM modulation scheme in terms of medial compartment knee
unloading (knee adduction angular impulse, KAAI) a...

## Key facts

- **NIH application ID:** 10016814
- **Project number:** 1I21RX003476-01
- **Recipient organization:** VA PUGET SOUND HEALTHCARE SYSTEM
- **Principal Investigator:** Patrick Mark Aubin
- **Activity code:** I21 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2020-10-01 → 2022-09-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10016814

## Citation

> US National Institutes of Health, RePORTER application 10016814, Robotic Knee Exoskeleton to Reduce Joint Loading and Improve Mobility in Veterans with Medial Compartment Knee Osteoarthritis (1I21RX003476-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10016814. Licensed CC0.

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