Powered Foot Prosthesis and Physical Therapy for Lower Limb Problem

Overseen By Michael Hyre, MS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: VA New York Harbor Healthcare System

Must not be taking: Non-prescribed opioids

Disqualifiers: Cognitive deficits, Uncontrolled diabetes, others

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

Compensation: Varies

Number of Visits: 11

Duration: 4 weeks

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial tests a new powered ankle-foot prosthesis to evaluate its effectiveness for individuals with a transfemoral (above-knee) amputation. Researchers aim to determine if adding physical therapy to the use of this prosthetic device improves walking and reduces pain more than using the device alone. Participants will be divided into two groups: one will receive the prosthesis with physical therapy, and the other will receive the prosthesis with standard training. Individuals who have used a prosthetic knee for over six months and can walk short distances without assistance may be suitable for this trial. As an unphased trial, this study offers a unique opportunity to contribute to innovative research that could enhance mobility and 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. However, if you use non-prescribed opioids or overuse any prescription drugs, you may not be eligible to participate.

What prior data suggests that this powered ankle-foot prosthesis is safe for individuals with transfemoral amputation?

Research shows that powered ankle-foot prostheses, such as the Ottobock emPOWER, are generally well-received by users. These devices mimic natural ankle movement, improving walking. Studies have found that powered prosthetics enhance ankle movement and strength, aiding those with lower limb amputations in daily activities.

Although specific safety details about side effects for this device aren't provided, the technology behind powered prosthetics has been in use for some time, suggesting general safety for users. However, as with any new treatment or device, some risks may still exist. Potential participants should discuss any concerns with their healthcare provider. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Unlike the standard of care for lower limb prosthesis, which typically involves fitting a powered ankle-foot prosthesis and standard physical training, the new approach integrates device-specific physical therapy. Researchers are excited because this intensive therapy not only involves personalized PT sessions but also includes a structured home exercise program. This tailored approach aims to enhance user comfort and mobility more effectively than conventional methods, potentially leading to better adaptation and improved daily life functionality for prosthesis users.

What evidence suggests that this powered device and physical therapy could be effective for lower limb problems?

Research has shown that powered ankle-foot prosthetic devices can aid individuals with lower limb amputations by enhancing ankle movement and strength. These devices mimic natural ankle motion, providing extra energy during walking. Studies also indicate that using a powered prosthesis can alleviate knee and lower back pain, common issues for amputees. In this trial, one group will receive a powered prosthesis with standard practice training, while another group will receive the powered prosthesis combined with intensive physical therapy. Combining physical therapy with a powered prosthesis may further enhance these benefits by offering specific exercises to improve movement and strength. Overall, a powered prosthesis, especially when paired with physical therapy, holds promise for improving daily life for those with above-knee amputations. ^{1 2 3 4 6}

Who Is on the Research Team?

Jason Maikos, PhD

Principal Investigator

Director, VISN 2 Gait and Motion Analysis Laboratory

Are You a Good Fit for This Trial?

This trial is for adults with a single above-knee amputation who use a microprocessor knee, can walk at least 30 meters unaided, and haven't had much physical therapy recently. It's not for those with significant other health issues, pregnant women in their second trimester or beyond, people over 287 pounds, major upper limb amputees, or those using similar powered devices.

Inclusion Criteria

I can walk on a treadmill for 5 minutes at my own pace, using handrails if needed.

I can walk 30 meters by myself without help.

I have had 8 or fewer physical therapy sessions for my amputation in the last 6 months.

Exclusion Criteria

I do not use illegal opioids or misuse prescription drugs.

I use or have used a powered ankle-foot prosthesis in the last 6 months.

I weigh more than 287 pounds.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Baseline Assessment

Participants undergo a full gait analysis, functional measures, neurocognitive/cognitive, and pain assessment using their current passive prosthesis

1 week

1 visit (in-person)

Treatment

Participants are fitted with a powered ankle-foot prosthesis. Group A receives an 8-session intensive PT intervention over 4 weeks, while Group B receives standard practice training

4 weeks

8 visits (in-person) for Group A, 1 visit (in-person) for Group B

Assessment

Participants undergo assessments including gait analysis, functional measures, neurocognitive/cognitive, and pain assessment after 4 and 8 weeks of prosthesis use

4 weeks

2 visits (in-person)

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Powered device with physical therapy
• Powered device with standard of practice

Trial Overview

The study tests a powered ankle-foot prosthesis on individuals with transfemoral amputation. Participants are split into two groups: one receives the device plus intensive physical therapy (PT), while the other gets the device with standard practice without formal PT. Their walking ability and pain levels are measured before and after using the device.

How Is the Trial Designed?

Group I: Powered device with physical therapy Experimental Treatment 1 Intervention

Subjects will be fitted with a powered ankle-foot prosthesis (Ottobock emPOWER) and provided an intensive device-specific physical therapy (PT) intervention. The subjects will complete, on average, 8 PT training sessions lasting 30 - 45 minutes each. The subjects will also be provided with a home exercise program.

Group II: Powered device with standard of practice Active Control 1 Intervention

Subjects will be fitted with a powered ankle-foot prosthesis (Ottobock emPOWER) and provided the current standard of practice training for use of this powered prosthesis. The prosthetist will confirm a stable and comfortable alignment and educate the subject on proper home usage. Next, the subject will undergo a 45 - 60 minute training with a physical therapist that is characteristic of the current standard of practice.

Powered device with physical therapy is already approved in United States for the following indications:

Approved in United States as Powered Ankle-Foot Prosthesis for:

• Transfemoral Amputation Rehabilitation

Who Is Running the Clinical Trial?

VA New York Harbor Healthcare System

Lead Sponsor

Trials

25

Recruited

14,400+

Walter Reed National Military Medical Center

Collaborator

Trials

149

Recruited

33,800+

Published Research Related to This Trial

The powered prosthetic device (BiOM) significantly increased ankle motion and power during stair ascent in individuals with transtibial amputation, normalizing ankle power generation compared to able-bodied controls.

Despite these improvements, users of the BiOM still relied on a hip strategy for stair ascent, indicating that additional training may be needed to fully leverage the benefits of the powered prosthetic.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Stair ascent kinematics and kinetics with a powered lower leg system following transtibial amputation. Aldridge, JM., Sturdy, JT., Wilken, JM.[2022]

Recent advancements in powered ankle-foot prostheses (PAFPs) highlight the use of brushless direct-current motors and energy storage systems, which enhance the prostheses' size and autonomy while maintaining effective walking velocity and gait symmetry.

The most effective control strategy combines high-level finite-state machines with low-level torque control, but future improvements are needed in weight reduction, energy efficiency, and the ability to navigate varied terrains like slopes and stairs.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Advances in Powered Ankle-Foot Prostheses. Chumacero, E., Masud, AA., Isik, D., et al.[2019]

Microprocessor prosthetic ankles (MPAs) significantly improve posture and reduce knee moment in individuals with transtibial amputation when standing on both level and inclined surfaces, compared to traditional energy storing and returning (ESR) feet.

Among the tested MPAs, the Meridium® Ottobock (MPA2) provided the best control of the Center of Pressure (CoP) across all conditions, indicating its potential for enhancing balance and stability in daily activities for amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Microprocessor prosthetic ankles: comparative biomechanical evaluation of people with transtibial traumatic amputation during standing on level ground and slope. Thomas-Pohl, M., Villa, C., Davot, J., et al.[2021]

A systematic review of 28 studies on unilateral trans-tibial amputees found that Energy Storage And Return (ESAR) and Powered ankle-foot units (PWR) significantly adapt push-off power based on walking speed, unlike Solid Ankle Cushion Heel (SACH) units.

The study suggests that push-off power is a crucial factor in selecting prosthetic ankle-foot units, as ESAR and PWR showed strong correlations with walking speed, indicating their potential for better performance in varying walking conditions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prosthetic push-off power in trans-tibial amputee level ground walking: A systematic review. Müller, R., Tronicke, L., Abel, R., et al.[2023]

Physical therapists need to understand the different types of prosthetic foot-ankle assemblies, as each type has unique advantages and disadvantages that can affect the management of patients with lower limb amputations.

Prosthetic foot selection should consider the patient's physical abilities, psychological needs, and financial situation, and more research is needed to objectively assess the functionality of these devices.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Prosthetic feet. State of the Art. Edelstein, JE.[2022]

The prototype microprocessor-controlled prosthetic foot (CESR) significantly improved push-off power and energy storage during walking for unilateral transtibial amputees compared to conventional and previously prescribed prosthetic feet, indicating enhanced biomechanical performance.

Despite these improvements in push-off mechanics, the CESR did not reduce the overall metabolic cost of walking, suggesting that further design modifications are needed to enhance walking efficiency for amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The effects of a controlled energy storage and return prototype prosthetic foot on transtibial amputee ambulation. Segal, AD., Zelik, KE., Klute, GK., et al.[2021]

The Proprio-foot®, a quasi-active microprocessor-controlled ankle prosthesis, significantly improved balance and quality of life in 45 patients compared to standard ankle prostheses, as measured by various assessments over a 34-day period.

Despite these improvements, there was no significant difference in energy expenditure (measured by oxygen uptake) between the Proprio-foot® and standard prostheses during treadmill walking.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of a microprocessor-controlled ankle-foot unit on energy expenditure, quality of life, and postural stability in persons with transtibial amputation: An unblinded, randomized, controlled, cross-over study. Colas-Ribas, C., Martinet, N., Audat, G., et al.[2022]

A training protocol for powered knee and ankle prostheses was developed and successfully implemented with 30 participants who had unilateral transfemoral or knee disarticulation amputations, focusing on essential mobility skills like walking, stair climbing, and sit-to-stand transitions.

After 1-3 training sessions, all participants were able to walk comfortably on level ground, and 27 out of 30 successfully performed all other functional activities, demonstrating the efficacy of the training in enhancing mobility for amputees using advanced prosthetic devices.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Functional Mobility Training with a Powered Knee and Ankle Prosthesis. Finucane, SB., Hargrove, LJ., Simon, AM.[2022]

In a study involving 12 individuals with unilateral transtibial amputations, the powered prosthetic ankle did not show significant differences in metabolic costs, daily step count, or walking speed compared to unpowered prostheses, indicating no universal functional benefits.

However, some participants reported increased self-reported ambulation and decreased frustration with the powered prosthesis, suggesting that individual experiences may vary and highlighting the importance of considering both subjective and objective measures in future prosthetic research.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The influence of powered prostheses on user perspectives, metabolics, and activity: a randomized crossover trial. Kim, J., Wensman, J., Colabianchi, N., et al.[2021]

A new powered prosthetic ankle joint was developed to support both walking and running, showing the ability to mimic the necessary torque and angle for these activities at speeds up to 2.6 m/s.

While the system performed well in simulating ankle movements, it struggled to provide sufficient torque at higher running speeds (4 m/s), indicating that adjustments in spring stiffness are needed for optimal performance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A powered prosthetic ankle joint for walking and running. Grimmer, M., Holgate, M., Holgate, R., et al.[2023]

In a study of 42 patients with dysvascular lower extremity amputation, significant improvements were observed in physical function measures during the prosthetic training phase, including walking distance, gait speed, and timed mobility tasks, all showing statistically significant enhancements (P < .001).

Despite these improvements, patients' gait speed and mobility remained below clinically important thresholds, suggesting ongoing limitations in community ambulation and an increased risk of falls, highlighting the need for tailored rehabilitation strategies.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Functional Outcomes After the Prosthetic Training Phase of Rehabilitation After Dysvascular Lower Extremity Amputation. Christiansen, CL., Fields, T., Lev, G., et al.[2022]

The ruggedized powered ankle-foot prosthesis, known as the Warrior Ankle (WA), allowed a participant to walk faster (1.15 m/s) and demonstrated better adaptability to varying terrain compared to the predicate prosthesis (0.80 m/s).

The WA achieved greater peak dorsiflexion angles (up to 27.9°) than the predicate prosthesis, indicating improved functionality and a closer match to natural ankle movement, although further design improvements are still needed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Toward Developing a Powered Ankle-Foot Prosthesis With Electromyographic Control to Enhance Functional Performance: A Case Study in a U.S. Service Member. Knight, AD., Bass, SR., Elrod, JM., et al.[2022]

Citations

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Effects of a Powered Ankle-Foot Prosthesis and Physical ...

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This prospective, multisite study will enroll 30 individuals with unilateral transfemoral limb loss.

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