Restoration of Normative Postural Control
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-99
SponsorNorth Carolina State University
About 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.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
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
Disqualifiers
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
Trial design
Design model
Parallel
Treatments tested in this trial
direct EMG controlled prosthetic ankle
DevicePatients are trained to use the powered prosthetic ankles
PT guided prosthetic training
BehavioralAmputees are trained to use prosthetic ankles
Treatment groups
50 Participants
are divided into 2 treatment groupsGroup A: dEMG groupExperimental treatment 2 interventions
Group B: Passive groupActive comparator 1 intervention
Trial outcomes
Primary outcomes
1
aCOM, anticipatory Center of Mass Excursion when the expected disturbance is introduced
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.
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 devicesSecondary outcomes
1
Frequency of stepping responses
Number of amputees to conduct steps to recover from disturbance divided by total number of disturbance, which they experienced.
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 devices2
Zero-time-lag cross correlation coefficients for bilateral ankle torque
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
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 devices3
Prosthesis Embodiment Scale
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.
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 devices4
Average muscle modules structure correlation
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.
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 devicesSponsors and contacts
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North Carolina State University
Lead sponsor
University of North Carolina, Chapel Hill
Collaborator
Source ClinicalTrials.gov