# Design and Evaluation of a Biarticular Prosthesis to Reduce Gait Compensations

> **NIH VA IK2** · VA PUGET SOUND HEALTHCARE SYSTEM · 2020 · —

## Abstract

Project Summary / Abstract
My proposed research and training program aims to improve the mobility and quality of life of veterans with
transtibial (TT) amputation through the development of a novel biarticular prosthesis, and to train me in
neuromuscular biomechanics, prosthetic engineering, and gait simulations through the guidance and support
of a strong multidisciplinary team of mentors, so that I can become a successful independent research
scientist. My long-term career goal is to design, develop and evaluate novel prosthetic, orthotic and assistive
devices for people with reduced mobility. Consistent with this goal, I am proposing to design, develop and
evaluate a novel biarticular prosthesis that addresses some of the limitations of current lower limb prostheses.
Approximately one million people in the US are living with lower limb loss. An important cause of mobility
impairment in this population is the loss of the ankle plantar flexors since these muscles are the primary
contributors to body support, forward propulsion and swing leg initiation during normal walking. The biarticular
gastrocnemius (GAS) has a role distinct from that of the soleus; it provides the dominant source of energy to
power the leg into swing phase. Without the GAS, compensatory changes of the remaining leg muscles are
necessary, including an increase in the concentric iliopsoas force to accelerate the leg into swing phase.
Current prosthetic limbs cannot replicate the physiologic function of the ankle plantar flexors. When walking
with conventional prosthetic foot-ankle systems, TT amputees show limited push-off power, and they use
adaptive gait strategies, such as increased hip flexor work on the prosthetic side during pre-swing, to
compensate for the lack of a biarticular GAS. These compensations are thought to contribute to the increased
metabolic cost of amputee walking.
To reduce the gait compensations typical of TT amputees, I am proposing to develop a novel biarticular
prosthesis (BP) with a clutched spring that spans the ankle and knee joint. The BP will have the ability
to generate net positive ankle joint work and to provide energy to power the leg into swing. I will use
musculoskeletal modeling and simulations of TT amputee gait to optimize the design of the BP, and I will use
gait analysis to evaluate the effect of the BP on gait. The BP has the potential to reduce gait compensations
and improve functional mobility in veterans with TT amputation. The proposal has three specific aims:
Aim 1: Using simulation, determine subject-specific optimal BP parameters.
Aim 2: Demonstrate that the TT amputee gait compensations typically seen with conventional passive-
elastic prostheses are reduced with the subject-specific optimal BP across a range of walking speeds.
Aim 3: Determine if the Optimal BP reduces the metabolic cost of walking.
To accelerate my training and facilitate my development into an independent research scientist, I have brought
together mentors...

## Key facts

- **NIH application ID:** 10023198
- **Project number:** 5IK2RX002130-05
- **Recipient organization:** VA PUGET SOUND HEALTHCARE SYSTEM
- **Principal Investigator:** Patrick Mark Aubin
- **Activity code:** IK2 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2020
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2016-11-01 → 2021-10-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10023198

## Citation

> US National Institutes of Health, RePORTER application 10023198, Design and Evaluation of a Biarticular Prosthesis to Reduce Gait Compensations (5IK2RX002130-05). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10023198. Licensed CC0.

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