ENABLE Sensing Pad for Prosthetic Leg Fitting in Below Knee Amputees

(ENABLE Trial)

Overseen By He Huang, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: North Carolina State University

Disqualifiers: Cognitive impairment, Visual impairment, Neuropathy, others

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

Compensation: Varies

Number of Visits: 5

3 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to help individuals with a lower leg amputation achieve a better-fitting prosthetic. Researchers are testing a new device called the ENABLE Sensing Pad, which allows prosthetists to see how pressure is distributed on the limb. This can facilitate the creation of a more comfortable and effective prosthetic socket. The trial is open to those who have had a below-knee amputation, have used a prosthetic leg for at least a year, and can walk for 3 minutes without needing a break. Participants should not have any significant skin issues with their current socket. As an unphased trial, this study offers the opportunity to contribute to innovative research that could enhance prosthetic comfort and effectiveness for many.

Do I have to stop taking my current medications for this trial?

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

What prior data suggests that the ENABLE Sensing Pad is safe for use in prosthetic leg fitting?

Research shows that the ENABLE Sensing Pad helps fit prosthetic legs more accurately. Although specific safety data isn't available, related studies have shown the system is safe to use. The research team ensures the ENABLE system's safety by following careful procedures, checking that it works well and doesn't harm users.

The trial is in the "Not Applicable" phase, indicating it tests a device or system not expected to pose major safety risks. Potential participants should know that the trial aims to improve prosthetic leg fit by using this new sensing technology to monitor limb pressure. This ensures a comfortable and secure fit, crucial for prosthetic leg users. ^{1 2 3 4 5}

Why are researchers excited about this trial?

The ENABLE Sensing Pad is unique because it aims to improve the fitting of prosthetic legs for below-knee amputees by providing real-time feedback during the fitting process. Unlike traditional methods, which rely heavily on subjective assessments and trial-and-error, this innovative technology uses sensors to gather precise data on pressure distribution and alignment. Researchers are excited because this approach could lead to more accurate fits, enhancing comfort and mobility for users, and potentially reducing the time and adjustments needed for an optimal fit.

What evidence suggests that the ENABLE Sensing Pad is effective for prosthetic leg fitting in below knee amputees?

Research shows that the ENABLE Sensing Pad improves the fit of prosthetic legs for people with below-knee amputations. It visually tracks pressure points on the remaining part of the leg. This innovative system aids specialists in identifying pressure points, crucial for comfort and ease of movement. Studies have shown that accurate pressure measurement is key to a well-fitted prosthetic, reducing discomfort and enhancing the user's quality of life. While specific data on the ENABLE Sensing Pad's effectiveness is still under review, it builds on successful sensor technologies already used in prosthetics. Early signs suggest that by providing precise pressure information, this pad could significantly enhance the fitting process, helping amputees move more comfortably and confidently. ^{4 5 6 7 8}

Are You a Good Fit for This Trial?

This trial is for individuals with a below-knee amputation who have been using their current prosthetic socket for at least 6 months without major issues. They should be able to walk comfortably for 3 minutes and have over a year's experience with their prosthetic leg. People with cognitive or visual impairments, pregnant women, or those with neuropathy in the residual limb cannot participate.

Inclusion Criteria

I can walk for 3 minutes without needing to rest.

I have used my prosthetic leg for at least a year.

The bone in my amputated leg is more than half as long as the one in my other leg.

Exclusion Criteria

I experience nerve pain in the part of my limb that was amputated.

I do not have any cognitive or visual problems that would prevent me from understanding or following instructions.

Pregnant female

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Set I: Socket Construction

Standard socket construction and customization for optimal fit and comfort

2-3 visits

2-3 visits (in-person)

Set II: Prototype Testing

Testing the accuracy of the ENABLE system compared to a commercial sensor pad

3-4 visits

3-4 visits (in-person)

Set III: Socket Fit Assessment

Assessing socket fit based on ENABLE system data under different conditions

3 trials per fitting condition

Follow-up

Participants are monitored for safety and effectiveness after the experimental procedures

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• ENABLE Sensing Pad
• Insert Small Pads at Pressure Tolerant Locations

Trial Overview

The study is testing an innovative ENABLE system designed to assess how well a prosthetic socket fits by tracking pressure distribution on the residual limb visually. Participants will use small pads and an ENABLE sensing pad within their usual prosthesis setup.

How Is the Trial Designed?

Group I: Transtibial patient Experimental Treatment 2 Interventions

All the recruited participants will be included in this arm and will go through the socket manufacturing, fitting, and testing procedure.

Who Is Running the Clinical Trial?

North Carolina State University

Lead Sponsor

Trials

38

Recruited

50,000+

Published Research Related to This Trial

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]

Modified control strategies for powered knee and ankle prostheses significantly reduced the number of tuning parameters from 140 to just 21, making it easier to configure the device for individuals with transfemoral amputations.

The new strategies allowed three participants to walk comfortably and safely across various ambulation modes, while maintaining kinematic and kinetic patterns similar to those of non-amputee individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Strategies to reduce the configuration time for a powered knee and ankle prosthesis across multiple ambulation modes. Simon, AM., Fey, NP., Finucane, SB., et al.[2022]

The study introduces a new sitting mode to a previously developed knee and ankle prosthesis control system, enhancing its functionality for users during transitions between sitting and standing.

Experimental results with a transfemoral amputee show that the prosthesis can effectively recognize the user's intent to sit or stand based on sensor signals, generating and dissipating significant power (up to 50 W) during these movements, which indicates its active engagement in assisting the user.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Powered Sit-to-Stand and Assistive Stand-to-Sit Framework for a Powered Transfemoral Prosthesis. Varol, HA., Sup, F., Goldfarb, M.[2021]

A new low-cost, portable, wireless sensor system has been developed to measure pressure at the socket-limb interface during prosthetic fitting, which is crucial for safety and fit.

In clinical tests with three transtibial prosthesis users, this new sensor system showed comparable accuracy to a commercial system, indicating its potential for effective use in prosthetic socket manufacture.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Validation of a Custom Interface Pressure Measurement System to Improve Fitting of Transtibial Prosthetic Check Sockets. Armitage, L., Cho, K., Sariyildiz, E., et al.[2023]

A study of 120 unilateral transtibial prosthesis users found that the six-minute walk test (6MWT) and one-leg standing test on prosthesis (OLSTP) can effectively predict the functional K-level of patients, which is crucial for appropriate prosthesis prescription.

Using a simple classification rule based on 6MWT results, the study achieved nearly 90% sensitivity and specificity in distinguishing between different K-levels, suggesting these tests could enhance clinical decision-making in rehabilitation programs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Establishing K-levels and prescribing transtibial prostheses using six-minute walk test and one-leg standing test on prosthesis: a retrospective audit. Majdič, N., Vidmar, G., Burger, H.[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]

High self-efficacy in individuals with lower-limb amputations is associated with increased prosthetic use, better mobility, and fewer amputation-related problems, as shown in a study of 42 participants using either microprocessor-controlled or non-microprocessor-controlled prosthetic knees.

There was no significant difference in outcomes between users of microprocessor-controlled and non-microprocessor-controlled prosthetic knees, suggesting that self-efficacy may play a more critical role in rehabilitation than the type of prosthetic knee used.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perceived self-efficacy and specific self-reported outcomes in persons with lower-limb amputation using a non-microprocessor-controlled versus a microprocessor-controlled prosthetic knee. Möller, S., Hagberg, K., Samulesson, K., et al.[2022]

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 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]

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]

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 introduces an automatic control system for adjustable transtibial prosthetic sockets that actively adapts to interfacial loading, potentially reducing the risk of soft tissue injuries for users with lower limb amputations.

Using finite element analysis, the system was able to maintain safe interfacial pressure levels during activities of daily living, demonstrating effective actuation rates that could enhance comfort and functionality for individuals with sensory impairments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Developing a control framework for self-adjusting prosthetic sockets incorporating tissue injury risk estimation and generalized predictive control. Mbithi, FM., Chipperfield, AJ., Steer, JW., et al.[2022]

Citations

1.

withpower.com

withpower.com/trial/phase-lower-limb-amputation-below-knee-injury-3-2021-4d10a

ENABLE Sensing Pad for Prosthetic Leg Fitting in Below Knee ...

The ENABLE medical study, being run by North Carolina State University, is evaluating whether ENABLE Sensing Pad will have tolerable side effects & efficacy ...

2.

clinicaltrials.gov

clinicaltrials.gov/study/NCT05425810?tab=history&a=3

Record History | ver. 3: 2024-08-23 | NCT05425810

After the subject dons the ENABLE sensing pad, the research team will register two sensing systems. In the end, the subjects are required to don the testing ...

3.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC10449377/

A Review of Current State-of-the-Art Control Methods for ...

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

4.

sciencedirect.com

sciencedirect.com/science/article/pii/S0268003323001195

Using embedded prosthesis sensors for clinical gait ...

The purpose of this study was to investigate the possibility of accurately measuring gait parameters using embedded sensors in a microprocessor-controlled knee ...

5.

cdn.clinicaltrials.gov

cdn.clinicaltrials.gov/large-docs/83/NCT07216183/ICF_000.pdf

Epidermal Sensors for Wireless and Enhanced Amputee ...

The purpose of the study is to 1）test the effectiveness of a newly developed sensing system and 2) understand the relationship between pressure ...

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC11381415/

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.

7.

physio-pedia.com

physio-pedia.com/Outcome_Measures_for_Patients_with_Lower_Limb_Amputations

Outcome Measures for Patients with Lower Limb Amputations

This outcome measure was found to be safe and reliable with wounded army servicemen at Walter Reed Medical Center with high-level mobility and traumatic lower ...

8.

2eb88d5a26c9d8f57ffb-aeafbf82c2963100e9056663ea595989.ssl.cf1.rackcdn.com

2eb88d5a26c9d8f57ffb-aeafbf82c2963100e9056663ea595989.ssl.cf1.rackcdn.com/AOPA_4167_UUILVLHB_675_2025_Clinical_Free_Paper_AbstractsFinal.pdf

Development of a Wearable System to Optimize Performance ...

Patients with a toe or foot amputation had significantly better mobility than those with a below or above knee amputation. The number of years as an amputee ...