AB Gait Estim Neurophysiology
ConditionGait
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-65
SponsorEmory University
About this trial
This study is being done to answer the question: What are the effects of electrical stimulation and stepping practice on connections between the brain and muscles? The long-term goal of this project is to develop novel, effective, and personalized rehabilitation protocols founded on an understanding of neurobiological mechanisms that combine electrical stimulation with gait training to improve gait performance in older adults and stroke survivors.
The rationale of this project is to explore and generate preliminary data regarding how electrical stimulation-based strategies modulate cortical and spinal circuits in able-bodied individuals.
The researchers will evaluate the effects of short treadmill walking bouts or single gait training sessions with and without electrical stimulation on somatosensory, spinal-reflex, corticospinal circuit neurophysiology, and/or gait performance.
The study will provide important preliminary and normative data that can explain how brain circuits change with stimulation or stepping practice and inform future rehabilitation studies on patients. The study population is able-bodied individuals.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
18-65 years
Able-bodied (healthy without any physical disability, neurological, orthopedic, or other medical disorder affecting walking or study protocol participation)
Ability to walk >10m overground and for 1 minute on a treadmill
Ability to follow 3-stage commands and provide informed consent.
Disqualifiers
Self-reported history or evidence of orthopedic or physical disability
History or evidence of neurological pathology
Pregnancy (female)
Uncontrolled hypertension
Trial design
Design model
Factorial
Treatments tested in this trial
Gait Training
Other interventionGait training: One or multiple short bouts of stepping practice on a treadmill at self-selected or fast speeds will be delivered without FES.
Functional electrical stimulation (FES)
DeviceElectrical stimulation involving the parameters and settings proposed here is commonly used in clinical practice and research for pain relief and other applications also referred to as neuromuscular or transcutaneous electrical nerve stimulation. The FES will be delivered using the UDel Stimulator, a custom-designed FES system from the University of Delaware FES lab. Researchers will use a customized, real-time system to control the stimulator and deliver stimulation during appropriate phases of the gait cycle. Stimulation will be delivered to the ankle dorsiflexors when the subject's foot is in the air (swing phase). Stimulation will be delivered to the ankle plantarflexors during the terminal stance phase of gait. 30-Hz variable frequency stimulation trains will be delivered during gait.
Peripheral electrical stimulation paired with cortical magnetic stimulation pulses
DeviceThe paired associative stimulation (PAS) will be conducted in a static posture (seated or standing), to evaluate effects on somatosensory, spinal-reflex, and/or corticospinal neurophysiology delivered with different stimulation parameters. One or multiple short bouts of stepping practice on a treadmill at self-selected or fast speeds may be completed before and/or after PAS to evaluate gait performance
Treatment groups
50 Participants
are divided into 3 treatment groupsGroup A: Gait with functional electrical stimulationExperimental treatment 2 interventions
Group B: Gait without functional electrical stimulationExperimental treatment 1 intervention
Group C: Paired stimulation of the cortex and peripheral nervous systemExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
Gait Performance
Marker data will be collected using a 7-camera motion analysis system at 120 Hz (Vicon, Oxford, UK). During treadmill walking, ground reaction forces during the treadmill walking will be collected using a treadmill instrumented with two 6-component force platforms under each belt (Bertec, USA). Ground reaction forces will be evaluated using a force plate embedded within the lab floor (AMTI, USA).
Time frame
Pretest (up to 60 seconds), during test (up to 36 minutes), post-test (up to 60 seconds)2
Corticospinal excitability
Corticospinal excitability will be assessed using a non-invasive technique called transcranial magnetic stimulation (TMS). TMS will be delivered using MagStim Stimulators with a double circular coil, custom-built double-cone, or batwing coil (Magstim Ltd, Wales, UK). Electrical activity from muscles in response to the TMS will be collected using surface EMG electrodes attached to muscles that play critical roles during walking (e.g., quadriceps femoris, tibialis anterior, soleus, gastrocnemius, hamstrings, etc.). In addition, EMG signals may be recorded from a couple of upper extremity muscles (e.g., first dorsal interosseus, flexor digitorum indicis) to be used as a control.
Time frame
Pretest (up to 60 seconds), during test (up to 36 minutes), post-test (up to 60 seconds)3
Spinal circuit excitability
Spinal excitability may be assessed using peripheral electrical stimulation delivered to the nerves innervating the ankle muscles. The methods for electrical stimulation are similar to those used for delivering functional electrical stimulation except that the subjects are seated and the stimulation is used to obtain outcome measures assessing spinal excitability. Muscles of interest are the soleus and medial gastrocnemius (calf muscles), and tibialis anterior (front of lower leg). EMG activity will be recorded while 50-60 electrical stimuli (short 1 ms square pulses, ranging in intensity from 1mA - 80 mA), 7-10 seconds apart, are delivered to the muscle. Researchers may also deliver 5-20 electrical stimulus pulses at intensities that elicit a percentage of the maximum reflex response.
Time frame
Pretest (up to 60 seconds), during test (up to 36 minutes), post-test (up to 60 seconds)Other outcomes
1
Muscle activity during gait
To record muscle activity, small electromyography (EMG) sensors may be attached to various muscles. The EMG sensors will be attached using hypo-allergenic adhesive. EMG signals will be recorded from the following muscles: tibialis anterior, soleus, gastrocnemius, quadriceps femoris, hamstrings, gluteus medius, and erector spinae
Time frame
Pretest (up to 60 seconds), during test (up to 36 minutes), post-test (up to 60 seconds)2
Somatosensory excitability
Somatosensory transmission and excitability may be assessed using electroencephalography (EEG) responses to peripheral nerve stimulation (PNS) stimuli delivered to the lower limb.
Time frame
Pretest (up to 60 seconds), during test (up to 36 minutes), post-test (up to 60 seconds)Sponsors and contacts
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Source ClinicalTrials.gov