EMG-Controlled Prosthetic Ankle for Below Knee Amputation

Overseen By Ming Liu, PhD

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: North Carolina State University

Disqualifiers: Congenital amputees, Powered prosthetic users, others

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

Compensation: Varies

Number of Visits: 18

50 Participants Needed

Trial Summary

What is the purpose of this trial?

The objective of this proposal is to investigate the effects of training to use direct electromyographic (dEMG) control of a powered prosthetic ankle on transtibial amputees'. The aimed questions to answer: 1. whether dEMG control will improve balance and postural stability of amputees, 2. whether dEMG control will lead to more natural neuromuscular control and coordination, 3) whether dEMG control will reduce cognitive processes. Participants will go through PT guided training on using dEMG controlled prosthetic ankles and are evaluated for their capability on functional tasks. The results will be compared with a comparison group, which goes through the same training but with their everyday passive prostheses on balance capability, neuromuscular coordination, and cognitive load during locomotion.

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's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment EMG-Controlled Prosthetic Ankle for Below Knee Amputation?

Research shows that using EMG signals to control a powered prosthetic ankle, combined with physical therapy, can improve balance and stability in people with below-knee amputations. A case study found that this approach led to better postural control and reduced reliance on other joints compared to a passive prosthesis. ^{1 2 3 4 5}

Is the EMG-controlled prosthetic ankle safe for humans?

The research suggests that using EMG signals to control a powered prosthetic ankle is feasible and can improve balance and postural control in individuals with below-knee amputations. However, the studies primarily focus on feasibility and functionality, and do not provide detailed safety data, indicating a need for further research to confirm safety in a larger group of participants. ^{1 2 3 4 6}

How does the EMG-controlled prosthetic ankle treatment differ from other treatments for below-knee amputation?

The EMG-controlled prosthetic ankle treatment is unique because it uses electromyographic (EMG) signals from the user's muscles to provide direct and continuous control of the prosthetic ankle, allowing for more natural movement and improved postural control. This approach, combined with physical therapy-guided training, enhances the user's ability to perform daily activities with better balance and less reliance on intact joints, unlike traditional passive prostheses that do not offer such dynamic control. ^{1 2 3 5 7}

Research Team

He Huang, PhD

Principal Investigator

NC State University

Eligibility Criteria

This trial is for individuals with below-knee amputations. Participants should be able to undergo physical therapy (PT) and use a direct electromyographic (dEMG) controlled prosthetic ankle. Specific inclusion or exclusion criteria are not provided.

Inclusion Criteria

Are willing to come to NC State University's Centennial Campus to participate in research and be photographed while doing research activities

I am 18 years old or older.

I can walk with some assistance.

Exclusion Criteria

I can understand and follow simple instructions.

Congenital amputees

Weight more than 300lbs

Timeline

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

1 visit (in-person)

Baseline Evaluation

Initial evaluation with both powered and passive prostheses to establish baseline measurements

2 weeks

4 visits (in-person)

Training

Participants undergo training to use the powered prosthetic ankle, focusing on muscle coordination and integration with full body motion

5 weeks

7 visits (in-person)

Post-training Evaluation

Evaluation of the impact of the training program on participants' performance with both prosthetic types

2 weeks

4 visits (in-person)

Follow-up

Participants are monitored for long-term effects of the training program on balance and postural control

4 weeks

2 visits (in-person)

Treatment Details

Interventions

• direct EMG controlled prosthetic ankle
• PT guided prosthetic training

Trial Overview The study tests if using dEMG control of a powered prosthetic ankle improves balance, neuromuscular coordination, and reduces cognitive load in transtibial amputees compared to those using passive prostheses.

Participant Groups

Group I: dEMG group Experimental Treatment 2 Interventions

Patients go through the training procedure with the direct EMG controlled powered prosthetic ankle.

Group II: Passive group Active Control 1 Intervention

Patients go through the training procedure with their own passive prosthetic ankles

direct EMG controlled prosthetic ankle is already approved in United States for the following indications:

Approved in United States as dEMG-controlled prosthetic ankle for:

• Transtibial amputation rehabilitation
• Balance and postural stability improvement
• Neuromuscular control and coordination enhancement

Who Is Running the Clinical Trial?

North Carolina State University

Lead Sponsor

Trials

38

Recruited

50,000+

University of North Carolina, Chapel Hill

Collaborator

Trials

1,588

Recruited

4,364,000+

Findings from Research

The study demonstrated that direct, continuous electromyographic (dEMG) control of a powered ankle prosthesis significantly improved standing postural control in a participant with a transtibial amputation, as evidenced by higher clinical balance scores compared to a passive prosthesis.

Using dEMG control led to synchronized muscle activation and a notable increase in postural stability, with a cross-correlation coefficient of .83 for center of pressure excursions, indicating enhanced control and reduced reliance on intact joints.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Direct continuous electromyographic control of a powered prosthetic ankle for improved postural control after guided physical training: A case study. Fleming, A., Huang, S., Buxton, E., et al.[2021]

Powered foot-ankle prostheses can significantly enhance the natural gait and energy efficiency of amputees, allowing for voluntary control of ankle movements, which aids in daily activities.

A study involving 12 trans-tibial amputees and 5 control subjects demonstrated that accurate real-time control of ankle joint movements can be achieved using electromyographic signals from as few as 4 muscles, with a mean error of only 5.3%.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Myoelectric neural interface enables accurate control of a virtual multiple degree-of-freedom foot-ankle prosthesis. Tkach, DC., Lipschutz, RD., Finucane, SB., et al.[2013]

Using electromyographic (EMG) signals from residual muscles can significantly enhance the control of robotic lower limb prostheses, allowing for more natural and adaptable movement for amputee users.

This review identifies both the potential benefits and challenges of EMG-based control, emphasizing the need for collaboration among researchers and clinicians to develop advanced bionic limbs that improve motor function.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Myoelectric control of robotic lower limb prostheses: a review of electromyography interfaces, control paradigms, challenges and future directions. Fleming, A., Stafford, N., Huang, S., et al.[2021]

A neural network approach using surface electromyography (sEMG) has been successfully developed to control a powered ankle prosthesis, predicting ankle angle and moment during walking with high accuracy using muscle data from healthy individuals.

The study identified optimal combinations of lower extremity muscles for controlling the prosthesis, with the combination of tibialis anterior and medial gastrocnemius showing the best performance, suggesting a pathway for creating more economical and flexible prosthetic devices for amputees.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Development of a neural network based control algorithm for powered ankle prosthesis. Keleş, AD., Yucesoy, CA.[2021]

Using electromyographic (EMG) signals from both native and reinnervated thigh muscles significantly improved the control of a robotic leg prosthesis for a knee-amputated patient.

The integration of EMG signals with sensor data allowed for intuitive movement control, enabling smooth transitions between different walking surfaces and repositioning while seated.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Robotic leg control with EMG decoding in an amputee with nerve transfers. Hargrove, LJ., Simon, AM., Young, AJ., et al.[2022]

Despite advancements in prosthetic technology, no commercially available prosthetic leg currently utilizes electromyography (EMG) signals for control, highlighting a gap in practical application.

A systematic review of 121 studies revealed that while there is significant research interest in using EMG for controlling lower limb prosthetics, challenges remain in signal quality, electrode placement, and control algorithms, indicating the need for further development before widespread use.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Electromyography-Based Control of Lower Limb Prostheses: A Systematic Review. Ahkami, B., Ahmed, K., Thesleff, A., et al.[2023]

A biofeedback training system was developed to assist above-knee amputees in learning to control their prosthetic knee, showing effectiveness in improving knee control for most users.

Out of 15 patients who completed the training program, 13 experienced significant benefits, indicating that while the system is generally effective, individual responses may vary.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Biofeedback training of knee control in the above-knee amputee. Fernie, G., Holden, J., Soto, M.[2022]

References

1. England pubmed.ncbi.nlm.nih.gov

Direct continuous electromyographic control of a powered prosthetic ankle for improved postural control after guided physical training: A case study. [2021]

2. United States pubmed.ncbi.nlm.nih.gov

Myoelectric neural interface enables accurate control of a virtual multiple degree-of-freedom foot-ankle prosthesis. [2013]

3. England pubmed.ncbi.nlm.nih.gov

Myoelectric control of robotic lower limb prostheses: a review of electromyography interfaces, control paradigms, challenges and future directions. [2021]

4. United States pubmed.ncbi.nlm.nih.gov

Development of a neural network based control algorithm for powered ankle prosthesis. [2021]

5. United States pubmed.ncbi.nlm.nih.gov

Robotic leg control with EMG decoding in an amputee with nerve transfers. [2022]

6. United States pubmed.ncbi.nlm.nih.gov

Electromyography-Based Control of Lower Limb Prostheses: A Systematic Review. [2023]

7. United States pubmed.ncbi.nlm.nih.gov

Biofeedback training of knee control in the above-knee amputee. [2022]