Hybrid Prosthetic Leg for Amputation

Overseen By Levi Hargrove, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Shirley Ryan AbilityLab

Disqualifiers: Cognitive impairment, Significant new injury, others

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

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: Unknown

20 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new type of prosthetic leg called the Hybrid Leg. The goal is to determine if this lightweight, powered leg can enhance the lives of people with lower limb amputations by evaluating its use in both lab settings and daily life. Participants will either try the Hybrid Leg or continue using their current prosthetic leg. Ideal candidates for the trial are those who have had one or both legs amputated and are already using a prosthesis for mobility. As an unphased trial, this study offers participants the chance to contribute to innovative research that could improve mobility solutions for amputees.

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 the Hybrid Prosthetic Leg is safe?

Research has shown that robotic prostheses, such as the Hybrid Leg, help people walk faster and with less effort. These devices are generally safe, especially when tested and used in controlled settings. Users of these prosthetic legs have a lower chance of falling compared to some other types of prosthetic knees. As a result, the Hybrid Leg is well-accepted and may offer a safer experience for users. ^{1 2 3 4 5}

Why are researchers excited about this trial's treatments?

Researchers are excited about the Hybrid Leg because it combines advanced technology to improve mobility for amputees. Unlike traditional passive prosthetic legs, which rely on the user's own motion to function, the Hybrid Leg integrates active components that can provide powered assistance and more natural movement. This innovative approach could lead to better balance, increased walking speed, and reduced fatigue for users, making daily activities easier and more comfortable.

What evidence suggests that this trial's prosthetic legs could be effective for amputation?

Research has shown that robotic prostheses like the Hybrid Leg, which participants in this trial may receive, help people walk faster and use less energy. Studies also indicate that these devices lower the risk of falling. The Hybrid Leg employs advanced controls to make walking smoother and more natural. Recent improvements in smart prosthetic limbs allow them to adjust to different walking speeds and needs. This technology aims to make walking more efficient and safe for users. Meanwhile, another group in this trial will use their currently prescribed passive prosthesis, serving as a comparison to evaluate the benefits of the Hybrid Leg. ^{1 3 6 7 8}

Who Is on the Research Team?

Levi Hargrove, PhD

Principal Investigator

Shirley Ryan AbilityLab

Are You a Good Fit for This Trial?

This trial is for individuals with a single or double lower limb amputation who currently use a prosthesis and can walk at various speeds (K2/K3/K4 level). Participants must speak English to understand the study and give feedback. Those with cognitive impairments, other serious health issues, or new injuries that prevent prosthesis use cannot join.

Inclusion Criteria

I have had one or both of my legs amputated.

English speaking

I can walk with a prosthesis.

Exclusion Criteria

I understand and can follow the study's requirements.

Significant other comorbidity: Any other medical issues or injuries that would preclude completion of the study, use of the prostheses, or that would otherwise prevent acquisition of useable data by researchers.

I can wear a prosthesis and do daily tasks without major new injuries.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

In-lab Therapy

Participants are fit with the Hybrid Leg and receive in-lab therapy to learn how to ambulate with the device

Duration not specified

Multiple in-lab visits

Ambulation and Community Mobility Training

Subjects complete extensive ambulation and community mobility training to learn optimal use of their own passive device or the Hybrid Leg

Duration not specified

Multiple in-lab visits

Home Trial

Subjects complete 4-week trials using their assigned prosthesis (Condition A or B) at home and within their community

4 weeks

Home-based monitoring

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Hybrid Leg
• Prescribed Passive Prosthesis

Trial Overview

The study tests an advanced powered prosthetic leg called 'Hybrid Leg' against the standard passive prosthesis prescribed to patients. The Hybrid Leg uses a special system designed to recognize the user's movement intentions in both lab settings and everyday life scenarios.

How Is the Trial Designed?

Group I: Condition B: Passive Leg Experimental Treatment 1 Intervention

Subject will use their currently prescribed home passive prosthesis

Group II: Condition A: Hybrid Leg Experimental Treatment 1 Intervention

Subject will be trained on use of the experimental device, the Hybrid Leg.

Who Is Running the Clinical Trial?

Shirley Ryan AbilityLab

Lead Sponsor

Trials

212

Recruited

17,900+

Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Collaborator

Trials

2,103

Recruited

2,760,000+

Published Research Related to This Trial

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]

The experimental adaptive controlled knee prosthesis significantly improved walking performance in amputees compared to a normal prosthesis, showing a 50% increase in hip moment peaks and a 37% reduction in hip muscular effort.

Additionally, the adaptive knee reduced the need for compensatory movements and enhanced walking symmetry, indicating its potential for better functional outcomes in amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Evaluation of AK prostheses comparing conventional with adaptive knee control devices. Ishai, G., Bar, A.[2019]

In a pilot study involving two participants with Syme amputation, crossover prosthetic feet demonstrated increased ankle range of motion and energy return compared to traditional energy-storing feet, suggesting a more natural gait pattern.

Both participants preferred the crossover feet, indicating potential benefits in user satisfaction, although changes in patient-reported outcomes were not statistically significant.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of high-profile crossover feet on gait biomechanics in 2 individuals with Syme amputation. Slater, C., Hafner, BJ., Morgan, SJ.[2023]

A study involving 29 active lower limb prosthesis users identified key themes related to mobility, which will help develop new items for the Prosthetic Limb Users Survey of Mobility (PLUS-M) to better assess the abilities of highly active individuals.

Participants highlighted the importance of understanding mobility characteristics, such as postural changes and terrain challenges, which can inform rehabilitation practices and improve access to specialized prosthetic components for enhanced mobility.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mobility with a lower limb prosthesis: experiences of users with high levels of functional ability. Morgan, SJ., Liljenquist, KS., Kajlich, A., et al.[2022]

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]

A study involving 15 lower limb prosthesis users found that patient-centered decision trees are effective tools for guiding users in self-managing socket fit issues, with 80% of participants agreeing on their acceptability.

The decision trees were particularly beneficial for new prosthesis users, as they provided clear solutions and used terminology that was easy to understand, while more experienced users may prefer to rely on their own self-management skills.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Development and acceptability testing of decision trees for self-management of prosthetic socket fit in adults with lower limb amputation. Lee, DJ., Veneri, DA.[2022]

In a study of 169 patients over 15 years, male gender and transtibial amputation were identified as strong predictors of successful prosthetic rehabilitation, while the presence of ulcers in the preserved limb was linked to rehabilitation failure.

Older age (especially over 65) and comorbidities were significant predictors of failed rehabilitation, highlighting the importance of timely physical therapy for improving walking ability post-amputation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Predicting successful prosthetic rehabilitation in major lower-limb amputation patients: a 15-year retrospective cohort study. Fajardo-Martos, I., Roda, O., Zambudio-Periago, R., et al.[2022]

Early ambulation after lower extremity amputation significantly improves functional and psychological outcomes, reduces risks associated with immobility, and enhances prosthetic compliance.

An indigenously developed, cost-effective temporary prosthesis allows for immediate fitting and early weight bearing, which helps prevent complications and increases acceptance among patients, particularly in Third World nations.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A cost-effective, adjustable, femoral socket, temporary prosthesis for immediate rehabilitation of above-knee amputation. Sathishkumar, S., Manigandan, C., Asha, T., et al.[2022]

The study developed a new method for configuring powered knee and ankle prostheses that significantly reduces the time needed to set them up for different walking modes, cutting the initial accommodation period by 56% to under 5 hours.

By using modified intrinsic control strategies, only 17% of the configuration parameters needed adjustment for novice users, making it easier for amputees to transition to using these advanced prosthetic devices.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Configuring a powered knee and ankle prosthesis for transfemoral amputees within five specific ambulation modes. Simon, AM., Ingraham, KA., Fey, NP., et al.[2022]

In a study of 112 patients with unilateral trans-tibial amputation, only 50% were fitted with a prosthesis at 6 months, with an additional 13% fitted by 8 years, highlighting challenges in prosthetic adoption post-amputation.

Significant predictors for receiving a prosthesis included younger age at amputation, ability to walk outdoors before the amputation, and being male, suggesting that these factors could guide patient management and rehabilitation strategies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Outcome after trans-tibial amputation for vascular disease. A follow-up after eight years. Hermodsson, Y., Ekdahl, C., Persson, BM.[2022]

A structured protocol for testing lower limb prostheses emphasizes safety, requiring users to meet specific graded safety levels before progressing to more challenging environments.

This approach aims to reduce the risk of falls and injuries, thereby enhancing user confidence and overall experience with active prosthetic legs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Design of a stepwise safety protocol for lower limb prosthetic risk management in a clinical investigation. Thesleff, A., Ahkami, B., Anderson, J., et al.[2022]

The study evaluated 14 different prosthetic feet for their energy storing and releasing capabilities using a young male amputee, ranking them based on total energy at the ankle joint during walking on level and sloped surfaces.

The top-performing prosthetic feet, which stored and released the most energy, were Flex-Walk, SAFE II, and High Function, while the subject preferred feet that absorbed more energy but released less, indicating a preference for comfort over energy return.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Energy storing property of so-called energy-storing prosthetic feet. Ehara, Y., Beppu, M., Nomura, S., et al.[2006]

In a study involving 10 individuals with unilateral transtibial limb loss, standardized functional prosthetic gait training did not show significant improvements in self-report measures or performance-based tests, except for the Amputee Mobility Predictor (AMPPRO) in those with peripheral vascular disease (PVD).

The Proprio foot demonstrated significant differences in mobility outcomes compared to other prosthetic feet, particularly in the AMPPRO and 6-minute walk test (6MWT), highlighting its potential benefits for users with PVD.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Application of self-report and performance-based outcome measures to determine functional differences between four categories of prosthetic feet. Gailey, RS., Gaunaurd, I., Agrawal, V., et al.[2022]

The Hybrid Knee prosthesis is designed to provide powered assistance specifically for stair climbing while remaining lightweight and passive for other activities like level-ground walking and stair descent.

Preliminary tests with both an able-bodied user and a transfemoral amputee showed low error rates in the system's ability to recognize when to switch between active and passive control, indicating effective intent recognition for improved ambulation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Ambulation Control System Design for a Hybrid Knee Prosthesis. Simon, AM., Ursetta, F., Shah, K., et al.[2022]

The study assessed the reliability and measurement error of performance-based clinical tests in 60 unilateral lower limb prosthesis (LLP) users, finding high interrater reliability (≥0.98) for all tests, indicating consistent results across different raters.

Test-retest reliability varied, with the Four Square Step Test showing the highest reliability (ICC of 0.97), while the Timed 'Up and Go' test had a lower reliability (ICC of 0.88), suggesting that most tests are suitable for clinical use in monitoring balance and mobility in LLP users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Interrater and Test-Retest Reliability of Performance-Based Clinical Tests Administered to Established Users of Lower Limb Prostheses. Sawers, A., Kim, J., Balkman, G., et al.[2020]

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Hybrid Prosthetic Leg for Amputation

This trial is for individuals with a single or double lower limb amputation who currently use a prosthesis and can walk at various speeds (K2/K3/K4 level).

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Virtual Constraint Control of a Powered Prosthetic Leg

This paper employs the method of virtual constraints on a powered prosthetic leg to unify the stance period, coordinate ankle and knee control, and accommodate ...

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Recent progress on smart lower prosthetic limbs

This review paper explores recent advancements in the integration of EEG and fNIRS modalities for smart lower prosthetic limbs for rehabilitation applications.

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In individuals with lower-limb amputations, robotic prostheses can increase walking speed, and reduce energy use, the incidence of falls and ...

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sciencedirect.com

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This research aims to address this issue by developing a fully mechanical trans-femoral prosthetic leg that is accessible to low-income people.

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In this paper, we present a review of existing control strategies for lower-limb powered prostheses, including the control objectives, sensing capabilities, ...

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Recent progress on smart lower prosthetic limbs

This review paper explores recent advancements in the integration of EEG and fNIRS modalities for smart lower prosthetic limbs for rehabilitation applications.