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NCT Number: NCT06452186

Restoration of Normative Postural Control

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.

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Key information

Conditions

Lower Limb Amputation Below Knee (Injury) Wounds and Injuries

Age range

18 year–99 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

Lab Visit Experience for Participants with lower limb amputation:

  • Number of Lab Visits: 15 visits. Clinicians may recommend skipping some of the visits or tasks based on clinical evaluation and status of the participants.
  • Length of Lab Visit: three hours maximum
  • First visit: the purpose of the first visit is to conduct consent and conduct measurements to decide walking speed and ABC (amputee balance confidence) score.
  • Second visit: this visit is to ensure that the amputees' own socket system can be integrated into the powered prosthetic leg and validate the effectiveness of the EMG interface.
  • Third and fourth visits: baseline evaluation with powered prosthesis and passive prosthesis. Each participant will finish the two visits. One of the visits is dedicated to their own passive prosthesis and the other visit is for the powered prosthesis. The sequence of the evaluation is randomized. The tasks conducted in the two visits are generally identical. The only difference is that one of the visits uses the participants' everyday prosthetic foot and the other uses the powered prosthetic ankle
  • Fifth and sixth visits: these visits are dedicated to have the participants trained to regain muscle coordination, which is critical to use the powered prosthetic ankle. All the participants will go through these trainings. Based on whether the participants are selected as the powered prosthetic group (Group A) or the passive group (Group B), the participants will finish this training with the powered prosthetic leg or a passive prosthetic leg.
  • Seven - eleventh visits: These visits are designed to give participants needed training, so participants are able to integrate the action of the powered prosthetic ankle with their full body motion for various tasks. To ensure that contribution of the training procedure to the performance changes are considered, all the participants will go through the training with the prostheses aligned with their group.
  • Twelfth-thirteenth visit (duplicate of Third and fourth visit). These visits are used to evaluate the impact of the training program on the performance of the participants to conduct tasks which are not included in the training procedure. Each participant will conduct the task with both passive and powered prosthetic legs on different days.
  • Fourteenth-fifteenth visits (duplicate of Third and fourth visit). These visits are used to understand the long term effects of the training program on the participants. These visits will be conducted three months after the 13th visits.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 18 years or older;
  • unilateral bower limb amputee
  • K-level 2 or higher (who are frequent prosthesis users and may benefit from the proposed prosthesis training and use of dEMG controlled powered prosthesis)
  • Amputation occurred over 2 years ago
  • At least 1 year of experience using their prosthetic leg
  • Has used the current socket for at least 6 months without a significant skin issue or major modification
  • Are willing to come to NC State University's Centennial Campus to participate in research and be photographed while doing research activities

Exclusion criteria

  • Have a very short residual shank (the length of the residual limb is ≤15% of the length of intact limb)
  • Cannot perform functional ambulation in the community on a daily basis without assistive devices
  • Cognitive or visual impairment that affects the participant's ability to provide informed consent or to follow simple instructions during the experiments
  • Congenital amputees
  • Amputees who use powered prosthetic ankles
  • Weight more than 300lbs
  • Pregnant Person
  • Allergic to latex, which is often contained in medical tapes.

Treatment and study plan

direct EMG controlled prosthetic ankle

Device

Patients are trained to use the powered prosthetic ankles

PT guided prosthetic training

Behavioral

Amputees are trained to use prosthetic ankles

Primary outcomes

  1. aCOM, anticipatory Center of Mass Excursion when the expected disturbance is introduced

    Time frame: Pre-training (before the training starts), Post-training (immediately after the training), and follow-up evaluation (one month) with both passive and dEMG devices

    This measurement is to quantify the movement of the COM at the time when the disturbance is introduced and represents an important element of the capability of the participants to conduct anticipatory. Higher value indicates better capacity to conduct anticipatory postural control.

Secondary outcomes

  1. Frequency of stepping responses

    Time frame: Pre-training (before the training starts), Post-training (immediately after the training), and follow-up evaluation (one month) with both passive and dEMG devices

    Number of amputees to conduct steps to recover from disturbance divided by total number of disturbance, which they experienced.

  2. Zero-time-lag cross correlation coefficients for bilateral ankle torque

    Time frame: Pre-training (before the training starts), Post-training (immediately after the training), and follow-up evaluation (one month) with both passive and dEMG devices

    Torque in the anterior-posterior direction. This outcome quantify the symmetry between the prosthetic ankle and the unaffected ankle when the participants try to maintain balance under expected disturbance

  3. Prosthesis Embodiment Scale

    Time frame: Pre-training (before the training starts), Post-training (immediately after the training), and follow-up evaluation (one month) with both passive and dEMG devices

    The Prosthesis Embodiment Scale for Lower Limb Amputees (PEmbS-LLA) measures amputees' feeling of ownership, sense of agency, and anatomical plausibility of a lower limb prosthetic device. This scale has been tested on lower limb amputees using daily prescribed prosthesis (not neurally controlled) with established validity and reliability. The score range is -3~3 and high value indicates better embodiment.

  4. Average muscle modules structure correlation

    Time frame: Pre-training (before the training starts), Post-training (immediately after the training), and follow-up evaluation (one month) with both passive and dEMG devices

    Correlation coefficient of muscle modules structures identified using nonnegative matrix factorization (NNMF) during a voluntary postural sway task. This measure is used to determine whether muscle modules employed between populations are meaningfully similar.

  5. Scores from Amputee Mobility Predictor (AMP) Test

    Time frame: Pre-training (before the training starts), Post-training (immediately after the training), and follow-up evaluation (one month) with both passive and dEMG devices

    Clinical balance outcomes used to measure the capacity of participants to conduct functional tasks, which are related to balance. The score ranges from 0-47. Higher values indicate better performance.

  6. Scores from MiniBES Test (Balance Evaluation Systems Test )

    Time frame: Pre-training (before the training starts), Post-training (immediately after the training), and follow-up evaluation (one month) with both passive and dEMG devices

    Clinical balance outcomes used to measure the capacity of participants to conduct functional tasks, which are related to balance. The score ranges from 0 to 28. The higher value indicates better balance capability

Study contacts

Contact information is provided by the study sponsor or research team.

Ming Liu, PhD

CONTACT

[email protected]

919-515-8543

Neuromuscular Rehabilitation Engineering Laboratory

CONTACT

[email protected]

919-513-3840

Sponsors and collaborators

Lead sponsor

North Carolina State University

Other

Collaborators

  • University of North Carolina, Chapel Hill

Registry information

Official study title

Toward Restoration of Normative Postural Control and Stability Using Neural Control of Powered Prosthetic Ankles

Important dates

Study start
2023
Primary completion
2028
Study completion
2028
First posted
Jun 11, 2024
Registry last updated
Jul 14, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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