Prosthetic Foot Adaptability for Amputation

Recruiting at 2 trial locations

Overseen By Monica Smersh

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: University of Washington

Disqualifiers: Skin wounds, Parkinson's, Alcoholism, others

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

Compensation: Varies

Number of Visits: 5

96 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to determine how different designs of prosthetic feet can enhance daily life for individuals with lower extremity amputations. Participants will test both a locked and an unlocked version of a new foot prosthesis, the META-Arc foot, to evaluate which offers better comfort, mobility, and ease in daily activities. The study will compare these new designs to each participant's usual prosthetic foot. The trial seeks individuals who have had an amputation for at least one year, use a prosthesis, and can walk over 400 meters without increased pain. As an unphased trial, it offers participants the chance to contribute to innovative research that could advance prosthetic technology and improve quality of life for many.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It seems focused on prosthetic foot use, so it's best to discuss your medications with the trial team.

What prior data suggests that this prosthetic foot is safe for people with lower extremity amputation?

Research has shown that the META-Arc prosthetic foot, in both its locked and unlocked versions, offers promising safety features based on mechanical testing. These tests revealed that the foot's design facilitates smooth side-to-side movement, which can reduce sideways forces and may lower the risk of falls or discomfort for users.

The META-Arc's ankle joint rotates side to side, similar to a natural human ankle, enhancing balance and comfort for individuals with lower-limb amputations. The locked version restricts this movement, providing a more stable option for those who need it.

Overall, studies suggest that both versions of the META-Arc foot enhance safety and comfort by reducing stress and increasing stability. However, as this is a new prosthetic foot, ongoing research and user feedback remain important to fully understand its safety in everyday use. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the META-Arc foot treatments because they offer innovative approaches to prosthetic foot adaptability for amputees. Unlike standard prosthetic feet, these treatments focus on adjustable ankle articulation, providing users with either locked or unlocked options. The unlocked condition allows for 20 degrees of frontal plane ankle motion, which could enhance natural movement and adaptability. Meanwhile, the locked condition eliminates this motion, potentially offering more stability. These options might lead to improved comfort and mobility for users, addressing varying needs in different situations.

What evidence suggests that the META-Arc foot is effective for improving mobility in people with lower extremity amputation?

Research has shown that the META-Arc prosthetic foot can improve balance and movement for people with leg amputations. In this trial, participants will join different arms to test the effectiveness of two versions of the META-Arc foot. The unlocked version, available to participants in one arm, allows for 20 degrees of movement, mimicking a natural ankle and reducing sideways pressure. This flexibility aids balance and eases walking. Meanwhile, the locked version, available to participants in another arm, limits side-to-side movement but still uses a special ankle joint to enhance stability. Both versions aim to make walking more comfortable and daily activities easier for users. ^{1 2 3 4 6}

Who Is on the Research Team?

Murray Maitland, PT, PhD

Principal Investigator

University of Washington

Are You a Good Fit for This Trial?

This trial is for individuals with above-knee amputations, bilateral amputations, or below-knee amputations who have lower mobility levels. It aims to help them with balance, pain, and daily activities by testing a new type of foot prosthesis.

Inclusion Criteria

I have been using a prosthesis for over a year since my amputation.

People must have the ability to read, write, and comprehend English.

I can walk more than 400 meters without feeling more pain.

Exclusion Criteria

Participants must not have conditions such as skin wounds that preclude the use of a prosthesis.

I do not have conditions like Parkinson's, alcoholism, brain tumor, or hereditary cerebellar ataxias that could affect my walking.

I can walk with help but don't mainly use a wheelchair.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

1 visit (in-person)

A1 Phase

Participants use their usual prosthetic foot and complete baseline assessments

2 weeks

1 visit (in-person)

B1 Phase

Participants use the investigational foot with either locked or unlocked linkage and perform community activities

2 weeks

1 visit (in-person), daily logbook entries

B2 Phase

Participants continue using the investigational foot with the opposite linkage condition and perform community activities

2 weeks

1 visit (in-person), daily logbook entries

A2 Phase

Participants return to using their usual prosthetic foot and reflect on differences

2 weeks

1 visit (in-person)

Follow-up

Participants are monitored for safety and effectiveness after the trial phases

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• META-Arc foot locked
• META-Arc foot unlocked

Trial Overview

The study tests a novel foot prosthesis in two modes: locked and unlocked. Participants will be randomly assigned to use either mode and their usual prosthetic foot to compare performance, comfort, and mobility.

How Is the Trial Designed?

Group I: Unlocked ankle articulation Experimental Treatment 1 Intervention

The design is a randomized cross-over clinical trial following an A1-B1-B2-A2 design. In the unlocked condition, the 20 degree of frontal plane ankle motion is enabled. The A conditions will be with the usual foot. The B conditions are randomized to the locked and unlocked investigational foot.

Group II: Locked ankle articulation Experimental Treatment 1 Intervention

The design is a randomized cross-over clinical trial following an A1-B1-B2-A2 design. In the locked condition, the 20 degree of frontal plane ankle motion is eliminated by a physical lock. The A conditions will be with the usual foot. The B conditions are randomized to the locked and unlocked investigational foot.

Who Is Running the Clinical Trial?

University of Washington

Lead Sponsor

Trials

1,858

Recruited

2,023,000+

United States Department of Defense

Collaborator

Trials

940

Recruited

339,000+

Published Research Related to This Trial

The META Arc prosthetic foot, featuring a polycentric ankle joint, significantly improves adaptability in the frontal plane and reduces lateral forces compared to six other commercially available prosthetic feet during testing on uneven terrain.

This design allows for better stability while walking without compromising forward motion performance, suggesting it could enhance the overall mobility of prosthesis users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mechanical testing of frontal plane adaptability of commercially available prosthetic feet. Wernke, MM., Ficanha, EM., Thomas, Z., et al.[2022]

A study involving 10 individuals with unilateral transtibial amputation found that a novel 3D-printed prosthetic foot (ComfyStep) showed significant biomechanical differences compared to conventional prosthetic feet, including reduced range of motion and increased stiffness.

While the 3D-printed foot allows for more individualized adjustments, the differences observed raise questions about its clinical relevance, suggesting that improvements in design, particularly in stiffness, could enhance its performance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Biomechanical comparison of a 3D-printed prosthetic foot with conventional feet in people with transtibial amputation: A prospective cohort study. Trinler, U., Heitzmann, DWW., Hitzeroth, S., et al.[2023]

Older adults with lower limb amputation reported significant adjustments in their lives post-amputation, highlighting the long-term impact of this experience.

Participants using the self-aligning ankle-foot (SA-AF) prosthetic reported less pain and greater mobility, indicating its acceptability and effectiveness, which supports the need for further research in a full-scale randomized controlled trial.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

'A whole different ball game': the qualitative experience of older adults with a transtibial amputation and the use of a self-aligning prosthetic ankle-foot on the STEPFORWARD trial. Mitchell, N., Leggett, H., Watson, J., et al.[2023]

The proposed compact, lightweight ankle-foot prosthesis utilizes a novel non-backdrivable cam-based transmission to actively reposition the foot during swing phases, which can enhance foot clearance and adapt to ground inclines.

Preliminary tests indicate that this new design could improve gait energetics, symmetry, and comfort for transtibial amputees, addressing the limitations of heavier powered devices and the Össur PROPRIO FOOT.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A lightweight robotic ankle prosthesis with non-backdrivable cam-based transmission. Lenzi, T., Cempini, M., Newkirk, J., et al.[2018]

Transtibial amputees using dynamic elastic response prostheses (like Seattle-Lite and Flex Foot) still walk slower and have shorter strides compared to non-amputee controls, indicating that these advanced designs do not fully restore normal mobility.

The study found that the timing and velocity of movements in the early stance phase were significantly delayed in amputees, which compromised their stability and suggests that future prosthetic designs should focus on improving ankle mobility to better mimic natural movement.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Segment velocities in normal and transtibial amputees: prosthetic design implications. Rao, SS., Boyd, LA., Mulroy, SJ., et al.[2022]

A 13-month clinical trial with 10 participants (average age 63) showed that individuals with transfemoral amputations classified as MFCL level K2 experienced significant improvements in gait performance, safety, and self-reported mobility when using a microprocessor-controlled knee (MPK) combined with a 1M10 foot, compared to their previous non-microprocessor knee (NMPK).

The improvements in clinical scores for gait speed, balance, and fall safety were comparable to those seen in individuals with a higher functional level (K3), suggesting that advanced prosthetic technology can enhance the quality of life for K2 level amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Using a microprocessor knee (C-Leg) with appropriate foot transitioned individuals with dysvascular transfemoral amputations to higher performance levels: a longitudinal randomized clinical trial. Jayaraman, C., Mummidisetty, CK., Albert, MV., et al.[2022]

A robotic prosthetic foot emulator (PFE) can accurately replicate the effective ankle stiffness of various commercial prosthetic forefeet, achieving an average accuracy within 1% of the actual feet tested.

This technology allows prosthesis users to trial different foot types based on their mechanical characteristics, potentially improving the decision-making process for prosthetic foot selection and enhancing user satisfaction.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Emulating the Effective Ankle Stiffness of Commercial Prosthetic Feet Using a Robotic Prosthetic Foot Emulator. Halsne, EG., Curran, CS., Caputo, JM., et al.[2022]

Individuals with unilateral lower limb amputation exhibit distinct turning strategies, spending more time on their intact limb compared to their prosthetic limb during a 180˚ turn, with transfemoral amputees showing even greater reliance on their intact limb than transtibial amputees.

The Component Timed-Up-and-Go (cTUG) test can effectively capture these differences in turning performance, which may inform prosthetic prescription and physical therapy interventions for amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Temporal-Spatial Values During a 180° Step Turn in People with Unilateral Lower Limb Amputation. Clemens, SM., Klute, GK., Kirk-Sanchez, NJ., et al.[2022]

In a study of 17 patients with lower limb amputations, bone-anchored prostheses showed a high implant survival rate of 90% at 2 years, 70% at 10 years, and 60% at 15 years, indicating long-term reliability.

Despite a significant improvement in functional scores for patients, 65% experienced mechanical complications and 76% had infections, primarily stage 1 infections, highlighting the need for careful monitoring post-surgery.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Bone-anchored prostheses for lower limb amputation in a French cohort with 1-15 years of follow-up: implant survival rates, mechanical complications, and reported outcomes. Thouvenin, C., Bertrand-Marchand, M., Klotz, R., et al.[2023]

Microprocessor Prosthetic Ankles (MPA) provide better ankle angle adaptation for transtibial amputees compared to traditional energy storing and return (ESR) feet, particularly during varied walking conditions like slopes and stairs.

However, while MPAs improve adaptability, they tend to release less energy for propulsion, indicating a trade-off between flexibility and energy efficiency in different prosthetic designs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Experimental characterization of the moment-angle curve during level and slope locomotion of transtibial amputee: Which parameters can be extracted to quantify the adaptations of microprocessor prosthetic ankle? Davot, J., Thomas-Pohl, M., Villa, C., et al.[2021]

Citations

1.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC9459498/

Mechanical testing of frontal plane adaptability ...

The results found the META Arc prosthetic foot had increased frontal plane adaptability as well as reduced lateral forces, and reduced inversion eversion ...

2.

researchgate.net

researchgate.net/figure/The-META-Arc-foot-with-a-polycentric-ankle-joint-that-rotates-and-shifts-the-foot-was_fig1_363378284

The META Arc foot with a polycentric ankle joint that rotates ...

A new prosthetic foot, the META Arc, was designed with a polycentric ankle joint that allows relatively free movement in the frontal plane to address this ...

3.

clinicaltrial.be

clinicaltrial.be/fr/details/422258?per_page=100&only_recruiting=1&only_eligible=0&only_active=0

Effectiveness of Frontal Plane Adaptability in a Novel Fo...

Participants are provided with the META-Arc from WIllowWood Global, and a locking mechanism prevents side-to-side motion. 2. META-Arc foot ...

4.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC11390102/

Motion Analysis of a Frontal Plane Adaptable Prosthetic Foot

The study hypothesizes that conditions resulting in increased frontal plane motion for control participants would be more likely to be achieved by an adaptable ...

5.

akjournals.com

akjournals.com/view/journals/1848/16/3/article-p499.xml

Modeling and simulation of a multi-axis ankle foot ...

Abstract This study investigates how to design and analyze a multi-axis prosthetic foot that replicates human foot movement characteristics.

6.

researchgate.net

researchgate.net/publication/363378284_Mechanical_testing_of_frontal_plane_adaptability_of_commercially_available_prosthetic_feet

(PDF) Mechanical testing of frontal plane adaptability of ...

Results The results found the META Arc prosthetic foot had increased frontal plane adaptability as well as reduced lateral forces, and reduced inversion ...