# Lightweight Powered Prosthesis for above-knee amputees

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2022 · $439,824

## Abstract

Project summary
 Most of the 400,000 Americans living with an above-knee amputation [3] cannot walk at variable speeds and
safely negotiate environmental barriers with their prescribed prostheses [4]. This limited functional mobility
severely affects their independence and results in secondary health problems, such as back pain, osteoarthritis,
and depression [5]. Powered prostheses have the potential to address these problems by providing energy for
climbing on ramps or stairs or standing up from a seated position, and by improving walking stability and foot
clearance. However, available powered devices are designed to accommodate the needs of young, strong
people, who overwhelmingly lose their limb due to trauma and can already achieve full community ambulation
with available passive prostheses.
 The objective of this proposal is to identify key prosthesis technologies required to improve the mobility level
of above-knee amputees form limited (K2) to community (K3) ambulators. Our central hypothesis is that a
lightweight powered prosthesis can facilitate a transition into variable-speed ambulation and the negotiation of
environmental barriers (K3 level) for those amputee patients who currently function at the upper end of the K2
level. Our previous work has produced the first powered knee and ankle prosthesis [11]–[15] to combine the
lightness of a passive device (~5.5 lbs) with the power generation capability of a powered prosthesis (~400 W)
[16]–[18]. In addition, we have developed an innovative control framework that automatically synchronizes the
movement of the powered prosthesis joints with the movement of the residual leg, while modulating energy
injection based on walking speed [19]. These novel lightweight prosthesis technologies have been preliminary
validated with able-bodied subjects and young traumatic above-knee amputees (K3-K4 level) walking on level
[20] and inclined ground at variable speeds, and climbing up and down stairs [12]. Moreover, our preliminary
experiments with three K2 above-knee subjects demonstrate the feasibility of the proposed approach.
The rationale for the proposed research is that understanding how lightweight robotic technologies contribute
to functional mobility will enable innovative design and prescription of prostheses that address the specific needs
of dysvascular and geriatric amputees, resulting in better healthcare, mobility, and quality of life.
 This contribution is significant because lightweight powered prostheses have the potential to extend longevity
and to dramatically improve quality of life for up to a million lower-limb amputees—a population expected to
double by 2050. Our approach is innovative because It leverages on a novel prosthesis technology that matches
the lightness of available passive prostheses without sacrificing power and torque generation capability to
address the specific needs of dysvascular patients for the first time. Cumulatively, this work is expected to provide
a comp...

## Key facts

- **NIH application ID:** 10155102
- **Project number:** 5R01HD098154-03
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Tommaso Lenzi
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $439,824
- **Award type:** 5
- **Project period:** 2019-09-09 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10155102

## Citation

> US National Institutes of Health, RePORTER application 10155102, Lightweight Powered Prosthesis for above-knee amputees (5R01HD098154-03). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10155102. Licensed CC0.

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