AzTrials
AzTrials

HealthyNCT05436366

Soleus Loading Response During Walking

A study testing Soleus loading response in able-bodied participants and Soleus loading response in participants with hemiparesis in people with Healthy and Spastic Hemiparesis, run by Victor H. Duenas at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
Search all trials

Trial summary

Stroke survivors experience motor deficits, weak voluntary muscle activations, and low weight-bearing capacity that impair ambulation. Restoring motor function is a priority for people post-stroke, whose gait patterns are slow, and metabolically inefficient. Read more about this study

Who is it for?
Ages 18 years and olderHealthy volunteers can take part
Conditions the study is for
Healthy, Spastic Hemiparesis, Stroke
What is being tested?
Soleus loading response in able-bodied participants and Soleus loading response in participants with hemiparesis
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
10 participants
Where
1 siteUnited States
Study dates
30 Sep 2022to 31 Aug 2024
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • For able-bodied individuals, the inclusion criterion is adults with no known neurological conditions or history of orthopedic injuries.
  • For individuals after stroke, inclusion criteria include participants who are neurologically stable for >6 months (and >1 year post stroke) and have medical clearance to participate in the study (with the expectation that current medication will be maintained without change for at least 4 months); ability to ambulate with or without an assistive device at least 10 m; and unilateral ankle extensor spasticity (hemiparesis); and able to wear the robotic ankle device, provide written informed consent and follow instructions.

Who cannot join

  • For able-bodied individuals, the exclusion criteria are motoneuron injury; a cardiac condition (history of myocardial infarct, pacemaker use); an unstable medical condition; and inability to provide written informed consent.
  • For individuals after stroke, the exclusion criteria are are a cardiac condition (history of myocardial infarction or congestive heart failure, pacemaker use); motoneuron injury (i.e., the neurons that give rise to the axons innervating the muscles); ambulation velocity of >1.2 m/s; a medically unstable condition (e.g., unstable angina, shortness of breath without exertion); musculoskeletal disorders that limit ambulation; and inability to provide informed consent.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • Syracuse University

    Syracuse, New York, 13244

Other trials in United States

About this study

Official title: Operant Conditioning of Loading Response During Locomotion in Able-bodied Individuals and People After Stroke

Stroke survivors experience motor deficits, weak voluntary muscle activations, and low weight-bearing capacity that impair ambulation. Restoring motor function is a priority for people post-stroke, whose gait patterns are slow, and metabolically inefficient. The role of the ankle is crucial for locomotion because it stores mechanical energy throughout the stance phase, leading to a large activation of plantarflexor muscles during push-off for propulsion.

After a stroke, paretic plantarflexors undergo changes in their mechanics and activation patterns that yield diminished ankle power, propulsion, and gait speed. Recovery of lost plantarflexor function can increase propulsion and mitigate unnatural gait compensations that occur during hemiparetic walking.

Read more

In the stance phase, dorsiflexion is imposed at the ankle and the plantarflexors are loaded, which results in excitation of group Ia and II afferents, and group Ib afferents. Load sensing Ib afferents are active in mid-late stance, and through spinal excitatory pathways, reinforces the activation of plantarflexors and propulsive force generation at the ankle. Targeting the excitability of the load sensitive Ib excitatory pathway, propulsive soleus activity and resulting force generation (and thereby gait speed) can be improved after stroke.

The long-term research goal is to develop a novel hybrid gait paradigm integrating operant conditioning and powered wearable devices to advance neuro-behavioral training and enhance locomotor ability after stroke. The overall objectives are to 1) modulate the soleus muscle loading response within the stance phase, and 2) develop a dynamic protocol to operantly condition the soleus response in stroke survivors. The central hypothesis is that enhancing the soleus loading response in mid-late stance phase through operant up-conditioning can increase plantarflexor power and forward propulsion after stroke.

In working towards attaining the research objective and testing the central hypothesis, the objective of this pilot study is to modulate the soleus loading response in the stance phase during treadmill walking. The specific aims in this study are to 1) apply ankle perturbations in mid-late stance phase combining a control algorithm and a powered device to characterize the changes in soleus EMG between perturbed and unperturbed (i.e., when no perturbations are applied) step cycles in 15 able-bodied individuals; and 2) determine the feasibility of the wearable ankle device and its algorithm in 5 participants with hemiparesis and gait deficits due to a stroke. The testing of the device and its algorithm will provide foundational evidence to adjust the soleus stimuli continuously and reliably, and develop the new walking operant conditioning protocol for stroke survivors.

An expected outcome in this pilot is to lay the groundwork to develop the soleus up-conditioning protocol as a potential strategy to improve paretic leg function. If successfully developed, this new protocol proposed in a subsequent study will be the first neurobehavioral training method that targets spinal load-sensitive pathways to improve ankle plantarflexor power and forward propulsion after stroke.

Read the detailed description

Participants are assigned to a single group in this basic science study. The protocol includes testing a wearable powered ankle device and its control algorithm during treadmill walking. The robotic ankle device is attached to the participant's calf and foot using a plastic ankle-foot orthosis and Velcro straps. The robotic ankle device will be worn on the impaired side while the contralateral side is free during walking. The participant places the foot (hemiparetic side) onto the robotic ankle device using the custom orthotic frame. The mechanical joint of the device is aligned with the participant's ankle joint center. A strap looped around the circumference of the shank attaches the participant's leg to the ankle device to ensure that the mechanical joint rotates the ankle joint. The fit should not be uncomfortably tight, but tight enough to prevent relative (unwanted) displacement. Cables are connected to a pair of electric motors that apply torque in the plantarflexion and dorsiflexion direction. The device collects measurements of the joint angle. The motors are regulated using the ankle joint angle such that the robotic device applies ankle rotation perturbations to induce changes in the soleus muscle activity. The ankle device integrates pressure sensors placed underneath the sole of the foot at the heel and toe to collect vertical ground reaction forces.

Electromyographic (EMG) sensors are placed on the soleus and tibialis anterior muscle groups. EMG sensors are glued using a biocompatible tape to affix the sensors to the skin. EMG activity is amplified, band-pass filtered (10-1000 Hz), sampled at 3,000 Hz, and stored. A study member will be available to assist participants to place the EMG sensors. Heart rate and blood pressure are monitored prior at the beginning of the protocol. Ankle, knee, and hip joint kinematics are recorded bilaterally using wearable electro-goniometers. Participants wear a safety harness which is attached to a portable system (overhead track and tripod) to prevent falling without restricting motion. An emergency stop button is available for participants to immediately halt the experiment. Participants can verbally request the staff to press the emergency stop button.

Participants walk at a self-selected comfortable fast speed (e.g., 3.5-4 km/h) during short bouts of treadmill walking (4-6 minutes per bout). The treadmill is controlled externally by a computer to adjust the speed of the belt. The gait session is expected to last about 60-90 minutes to avoid fatigue and time-varying changes in the muscle responses. During warm-up, the plantarflexor maximum voluntary contraction (MVC) is collected in a standing position, and gait kinematics, muscle EMG and ground reaction forces are recorded walking without wearing the robotic ankle device.

Following warm-up, while walking on the treadmill wearing the robotic device, ankle rotations will be applied using the developed algorithm to evoke the soleus loading response during the mid-late stance phase. The control algorithm applies ankle perturbations, which are shifts from the natural ankle kinematics to target the soleus loading response in mid-late stance phase every other 4-6 gait cycles to prevent habituation. Perturbation magnitude, speed, and timing are controlled during treadmill walking. Due to the unique parameters of the perturbation (magnitude and speed) applied by the device, there is minimal fall risk because it is applied for a short duration in the stance phase to evoke a muscle response (e.g., it is analogous to a mechanical stretch reflex). Hence, the perturbation is not applied to guide or assist the ankle motion, which will have a major influence in the gait kinematics. Outside of the window of perturbation within stance, the ankle control is turned off.

For any step cycle, only two conditions are possible. Either the participant is in a perturbed or unperturbed condition. During perturbed step cycles, the participant is wearing the ankle device and it applies force to change the ankle-foot motion (i.e., the device is activated). During unperturbed step cycles, the participant is wearing the ankle device, but it does not apply force to change the ankle-foot motion (i.e., the device is passive and not active).

A gait session consists of 4-5 walking bouts interleaving perturbed and unperturbed walking steps (until collecting data of about 30 perturbed and unperturbed steps per walking bout) leaving at least one unperturbed step before a perturbed step. Rest breaks are provided in between bouts.

The study team will continuously monitor the participant during a gait session and verbally request feedback to ensure the participant's comfort and safety. Automatic and manual software safeguards are placed to stop the session if the performance exceeds safe/desired speed or torque ranges. The gait session is finished with a cool down to measure joint kinematics, muscle EMG, and propulsion walking without wearing the device. At the end of the experiments, the wearable sensors will be gently removed from the body. The study staff will help the participant to take off the ankle device.

The study involves a single group enrolling 15 individuals with no known neurological conditions or history of orthopedic injuries. Changes in the soleus EMG will be compared between perturbed and unperturbed walking steps during a gait session. For the primary measure (soleus EMG response), the difference between the non-perturbed and perturbed EMG will be assessed by Student's t-test The sample size for able-bodied individuals allows us to estimate, with a two-sided 95% confidence level each, the soleus EMG response to perturbation within a margin of error of 5.4% non-perturbed EMG. This calculation is based on a previous study, where a group analysis with a s.d. of 0.87% change (% non-perturbed EMG) was observed in the soleus EMG in response to 1 deg/s joint motion perturbation during the mid-late stance phase (i.e., the variation in the soleus EMG is linearly related to the velocity and/or amplitude of the perturbations). A similar s.d. is assumed for the proposed study, which yields a sample size of N=15 able-bodied individuals. In addition, a sample size of 5 participants with hemiparesis and gait deficits due to a stroke will be studied to examine the feasibility of the proposed algorithms and device to evoke the soleus loading response. Due to the lack of availability of data with post-stroke participants, s.d. change % unperturbed soleus EMG cannot be defined prior to conducting testing with individuals after stroke. Hence, this pilot study will provide preliminary results to characterize the soleus EMG due to the applied perturbations in people post-stroke.

Being tested
Soleus loading response in able-bodied participants, Soleus loading response in participants with hemiparesis
Keywords
Gait, Exoskeleton, EMG
Medical subject headings
Hemiplegia, Stroke

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Soleus loading response in able-bodied participantsDevice

    Able-bodied participants are enrolled. The robotic ankle device applies ankle joint rotations using a computer-controlled closed-loop algorithm to evoke the soleus loading response during the mid-late stance phase during treadmill walking at a self-selected comfortable fast speed. The algorithm applies ankle perturbations, which are shifts from the natural ankle kinematics to target the soleus loading response in mid-late stance phase every other 4-6 gait cycles. The perturbation magnitude, speed, and timing are controlled by the device to adjust the participant's soleus response. Four-to-five walking bouts are conducted interleaving perturbed and unperturbed walking steps (until collecting data of about 30 perturbed and unperturbed steps per walking bout) leaving at least one unperturbed step before a perturbed step. Changes in the soleus EMG will be compared between perturbed and unperturbed walking steps.

  • Soleus loading response in participants with hemiparesisDevice

    Participants with spastic hemiparesis due to a stroke are enrolled. The robotic ankle device applies ankle joint rotations using a computer-controlled closed-loop algorithm to evoke the soleus loading response during the mid-late stance phase during treadmill walking at a self-selected comfortable fast speed. The algorithm applies ankle perturbations, which are shifts from the natural ankle kinematics to target the soleus loading response in mid-late stance phase every other 4-6 gait cycles. The perturbation magnitude, speed, and timing are controlled by the device to adjust the participant's soleus response. Four-to-five walking bouts are conducted interleaving perturbed and unperturbed walking steps (until collecting data of about 30 perturbed and unperturbed steps per walking bout) leaving at least one unperturbed step before a perturbed step. Changes in the soleus EMG will be compared between perturbed and unperturbed walking steps.

Study groups in NCT05436366
Study groupRoleWhat they receive
Soleus Loading Response ExperimentalExperimentalParticipants in this one arm will be administered the soleus loading response protocol by applying an ankle joint rotation during treadmill walking
Receives: Device: Soleus loading response in able-bodied participants; Device: Soleus loading response in participants with hemiparesis

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in soleus EMG response

    Changes in the soleus EMG response is the primary measure, which is the difference between the non-perturbed and perturbed EMG (i.e., the difference between the EMG obtained during step cycles with and without the applied ankle joint perturbation).

    Measured: From enrollment to end of intervention at approximately 1 week

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 Jun 2022
  2. Study start30 Sep 2022
  3. Primary completion31 Jul 2024
  4. Study completion31 Aug 2024

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Model description
Single arm
Masking
None (open label)
Enrolment
10 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05436366
Sponsor's protocol ID
SU-22-026
Other IDs
P2CHD086844
Status last verified
Nov 2024
First submitted
15 Jun 2022
Last updated
29 Nov 2024
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
Undecided: It is undecided to make IPD available to other researchers. The PI will seek further consultation to the IRB Office at Syracuse University.

Questions about this trial

What is this clinical trial studying?

A study testing Soleus loading response in able-bodied participants and Soleus loading response in participants with hemiparesis in people with Healthy and Spastic Hemiparesis, run by Victor H. Duenas at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 29 Nov 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in soleus EMG response (time frame: From enrollment to end of intervention at approximately 1 week). It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 29 Nov 2024.

Free account

Keep searching with a free account

You’ve used your 3 free searches for this session. Log in or create a free AzTrials account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in