Soleus Loading Response During Walking
Primary Purpose
Healthy, Spastic Hemiparesis, Stroke
Status
Recruiting
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Soleus loading response in able-bodied participants
Soleus loading response in participants with hemiparesis
Sponsored by
About this trial
This is an interventional basic science trial for Healthy focused on measuring Gait, Exoskeleton, EMG
Eligibility Criteria
Inclusion Criteria:
- 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.
Exclusion Criteria:
- 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.
Sites / Locations
- Syracuse UniversityRecruiting
Arms of the Study
Arm 1
Arm Type
Experimental
Arm Label
Soleus Loading Response Experimental
Arm Description
Participants in this one arm will be administered the soleus loading response protocol by applying an ankle joint rotation during treadmill walking
Outcomes
Primary Outcome Measures
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).
Secondary Outcome Measures
Full Information
NCT ID
NCT05436366
First Posted
June 15, 2022
Last Updated
April 15, 2023
Sponsor
Victor H. Duenas
Collaborators
Medical University of South Carolina, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
1. Study Identification
Unique Protocol Identification Number
NCT05436366
Brief Title
Soleus Loading Response During Walking
Official Title
Operant Conditioning of Loading Response During Locomotion in Able-bodied Individuals and People After Stroke
Study Type
Interventional
2. Study Status
Record Verification Date
April 2023
Overall Recruitment Status
Recruiting
Study Start Date
September 30, 2022 (Actual)
Primary Completion Date
August 15, 2023 (Anticipated)
Study Completion Date
August 31, 2023 (Anticipated)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Sponsor-Investigator
Name of the Sponsor
Victor H. Duenas
Collaborators
Medical University of South Carolina, Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Data Monitoring Committee
No
5. Study Description
Brief 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. 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.
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.
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.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Healthy, Spastic Hemiparesis, Stroke
Keywords
Gait, Exoskeleton, EMG
7. Study Design
Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Model Description
Single arm
Masking
None (Open Label)
Allocation
N/A
Enrollment
20 (Anticipated)
8. Arms, Groups, and Interventions
Arm Title
Soleus Loading Response Experimental
Arm Type
Experimental
Arm Description
Participants in this one arm will be administered the soleus loading response protocol by applying an ankle joint rotation during treadmill walking
Intervention Type
Device
Intervention Name(s)
Soleus loading response in able-bodied participants
Intervention Description
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.
Intervention Type
Device
Intervention Name(s)
Soleus loading response in participants with hemiparesis
Intervention Description
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.
Primary Outcome Measure Information:
Title
Change in soleus EMG response
Description
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).
Time Frame
From enrollment to end of intervention at approximately 1 week
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
Accepts Healthy Volunteers
Eligibility Criteria
Inclusion Criteria:
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.
Exclusion Criteria:
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.
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Victor H Duenas, PhD
Phone
3154433924
Email
vhduenas@syr.edu
First Name & Middle Initial & Last Name or Official Title & Degree
Jonathan Casas, MS
Phone
3154472382
Email
jacasasb@syr.edu
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Victor H Duenas, PhD
Organizational Affiliation
Syracuse University
Official's Role
Principal Investigator
Facility Information:
Facility Name
Syracuse University
City
Syracuse
State/Province
New York
ZIP/Postal Code
13244
Country
United States
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Victor Duenas, PhD
Phone
352-215-6548
Email
vhduenas@syr.edu
First Name & Middle Initial & Last Name & Degree
Jonathan Casas, MS
Phone
3154472382
Email
jacasasb@syr.edu
First Name & Middle Initial & Last Name & Degree
Victor Duenass, PhD
12. IPD Sharing Statement
Plan to Share IPD
Undecided
IPD Sharing Plan Description
It is undecided to make IPD available to other researchers. The PI will seek further consultation to the IRB Office at Syracuse University.
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Soleus Loading Response During Walking
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