Powered Knee Prosthesis for Above-Knee Amputation

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Massachusetts Institute of Technology

Disqualifiers: Pregnancy, Severe comorbidity, Poor health, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

Duration: 1 week

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores the effectiveness of the MIT Powered Knee, a powered knee prosthesis, for individuals with a transfemoral amputation (above-knee amputation). The research examines how this prosthesis impacts walking, movement control, and the sensation of it being part of the body. Participants will either use their regular prosthesis or try the experimental MIT Powered Knee. Ideal candidates have had one leg amputated above the knee and can walk at varying speeds. As an unphased trial, this study allows participants to contribute to innovative research that could improve prosthetic technology for future users.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

What prior data suggests that this powered knee prosthesis is safe for people with a transfemoral amputation?

Research has shown that the MIT Powered Knee prosthesis is generally safe. Studies have not identified any specific safety issues or negative effects with this device, suggesting that users tolerate the powered knee well. The device aids people with above-knee amputations in walking more naturally and simplifies tasks like climbing stairs and avoiding obstacles. So far, evidence indicates a positive safety record, making it a promising option for those considering participation in trials with this prosthesis. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike the standard prosthetic options for above-knee amputations, which typically rely on passive mechanisms, the MIT Powered Knee introduces active, powered assistance. This prosthesis uses advanced motors and sensors to mimic natural knee movement, providing a more natural gait and potentially reducing the physical effort required for walking. Researchers are excited about this innovation because it could significantly enhance mobility and comfort for users, offering a more dynamic and responsive experience compared to traditional prosthetics.

What evidence suggests that the MIT Powered Knee is effective for transfemoral amputation?

Research has shown that the MIT Powered Knee, which participants in this trial may receive, helps people with above-knee amputations walk more naturally and improve mobility. Users can walk faster and climb stairs more easily with this prosthetic leg compared to traditional ones. The powered knee also enables users to avoid obstacles better, making everyday activities safer and easier. Initial findings suggest that this advanced prosthetic restores more natural movement, offering significant benefits. Overall, evidence supports the effectiveness of the MIT Powered Knee in enhancing the quality of life for people with above-knee amputations. ^{1 2 3 4 6}

Who Is on the Research Team?

Hugh M Herr, PhD

Principal Investigator

Massachusetts Institute of Technology

Are You a Good Fit for This Trial?

This trial is for individuals who have had a below-knee amputation and are looking to improve their mobility. Participants should be able to walk with a prosthesis and commit to the study requirements. Specific eligibility details, such as age range or health status, are not provided.

Inclusion Criteria

My body can support the medical device properly.

I am between 22 and 65 years old.

I have had one leg amputated above the knee.

Exclusion Criteria

I am currently pregnant.

I do not have severe health issues that would prevent me from being a good candidate for the study.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants use either their prescribed prosthesis or the MIT powered knee prosthesis to assess clinical and functional outcomes

1 week

2 sessions

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• MIT Powered Knee

Trial Overview

The study is testing the MIT Powered Knee, an advanced prosthetic knee designed to enhance walking and movement control for those with transfemoral amputations. The focus is on how this device affects gait, spatial management, and the user's sense of integration with the prosthesis.

How Is the Trial Designed?

Group I: MIT Powered Knee Experimental Treatment 1 Intervention

Subjects wears the MIT powered knee prosthesis.

Group II: Prescribed prosthesis Active Control 1 Intervention

Subjects wears their prescribed prosthesis.

Who Is Running the Clinical Trial?

Massachusetts Institute of Technology

Lead Sponsor

Trials

104

Recruited

12,810,000+

U.S. Army Medical Research and Development Command

Collaborator

Trials

296

Recruited

249,000+

Published Research Related to This Trial

Transfemoral amputees typically experience higher metabolic costs while walking due to the limitations of passive prostheses, which do not effectively mimic the biomechanics of natural legs.

This study indicates that using a lightweight powered prosthesis that generates knee power during late stance can potentially enhance walking ability and reduce the effort required for ambulation in transfemoral amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Preliminary Analysis Of Positive Knee Energy Injection In A Transfemoral Amputee Walking With A Powered Prosthesis. Hood, SA., Lenzi, T.[2020]

In a study involving 41 individuals with above-knee amputations, those with higher functional mobility levels showed significant improvements in performance speed when using microprocessor-controlled prosthetic knee joints compared to mechanically controlled ones.

The results indicate that while there is considerable variability in functional performance among MFCL-2 amputees, many can benefit from the advanced technology of microprocessor-controlled knees for daily activities.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Functional added value of microprocessor-controlled knee joints in daily life performance of Medicare Functional Classification Level-2 amputees. Theeven, P., Hemmen, B., Rings, F., et al.[2014]

Current lower limb prostheses lack the ability to replicate the energy distribution and function of natural musculature, which is crucial for effective movement.

The proposed above-knee prosthesis incorporates a self-energized mechanism that captures and stores energy from passive movements at the knee and ankle, enabling active plantar-flexion and improving locomotion efficiency.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Active plantar-flexion above-knee prosthesis: concept and preliminary design. Rigas, C.[2017]

The new robotic leg prosthesis effectively mimics the biomechanics of a biological leg while matching the weight, size, and battery life of traditional prostheses, making it more practical for daily use.

Preclinical tests with three individuals showed that this prosthesis allows for natural walking movements and includes a passive mode for unlimited walking on level ground without needing to recharge, which is a significant advancement over existing powered prosthetics.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A lightweight robotic leg prosthesis replicating the biomechanics of the knee, ankle, and toe joint. Tran, M., Gabert, L., Hood, S., et al.[2023]

A case study demonstrated that lightweight powered knee and ankle prostheses can effectively restore natural leg movements for individuals with bilateral above-knee amputations, allowing them to walk and climb stairs with improved gait patterns.

The powered prostheses were able to replicate essential biomechanical functions, such as ankle push-off during walking and knee power generation during stair ascent, which are crucial for enhancing mobility and quality of life.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Powered knee and ankle prostheses enable natural ambulation on level ground and stairs for individuals with bilateral above-knee amputation: a case study. Hood, S., Creveling, S., Gabert, L., et al.[2023]

In a study comparing prosthetic knee systems for U.S. military service members with transfemoral amputations, the Power Knee™ (PK) showed greater peak knee power in the amputated limb during sit-to-stand tasks compared to the C-Leg, suggesting enhanced performance for PK users.

Despite the differences in knee power, both prosthetic systems resulted in greater forces on the intact limb, indicating that while PK may improve certain tasks, it does not significantly reduce impact on the remaining joints compared to the C-Leg.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of the Power Knee and C-Leg during step-up and sit-to-stand tasks. Wolf, EJ., Everding, VQ., Linberg, AA., et al.[2022]

Citations

1.

news.mit.edu

news.mit.edu/2025/bionic-knee-integrated-into-tissue-can-restore-natural-movement-0710

A bionic knee integrated into tissue can restore natural ...

The new bionic knee can help people with above-the-knee amputations walk faster, climb stairs, and avoid obstacles more easily than they could with a ...

2.

withpower.com

withpower.com/trial/phase-transfemoral-amputation-3-2008-f71e5

Powered Knee Prosthesis for Above-Knee Amputation

Research shows that powered knee prostheses can help people with above-knee amputations walk more naturally and climb stairs, improving their mobility and ...

3.

clinicaltrials.gov

clinicaltrials.gov/study/NCT06700668

Study Details | NCT06700668 | Active Knee Prosthesis Study

The patient must have a unilateral transfemoral amputation . The patient must have the ability to ambulate at variable cadence (an expected lower extremity ...

4.

sciencedirect.com

sciencedirect.com/science/article/abs/pii/S1350453321001442

Early evaluation of a powered transfemoral prosthesis with ...

These early results suggest the efficacy of simplifying impedance control tuning and fusing control and energy regeneration in transfemoral prostheses.

5.

dspace.mit.edu

dspace.mit.edu/bitstream/handle/1721.1/163444/petelina-petelina-meche-phd-2025-thesis.pdf?sequence=1&isAllowed=y

Integrated Prosthetic Leg Design Frameworks for People ...

ABSTRACT. A well-fitting, high-performance prosthesis for people with a lower limb amputation can greatly improve users' mobility and ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC7849323/

Effects of a Powered Knee-Ankle Prosthesis on Amputee ...

This paper investigates residual hip compensations through walking experiments with three transfemoral amputees using a low-impedance powered knee-ankle ...