Operant H-reflex Down-conditioning of Rectus Femoris in Post-stroke Stiff Knee Gait

Study Overview
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Brief Summary
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The investigators performed a feasibility trial of operant conditioning of spinal reflex excitability on five healthy individuals and two post-stroke individuals. The investigators found that operant conditioning of rectus femoris reflex excitability was feasible in all participants.

Detailed Description
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The investigators performed a cohort study on 7 individuals (5 healthy, 2 post-stroke) to examine the feasibility of operant down-conditioning of rectus femoris reflex excitability (i.e. H-reflex). Each individual performed 30 sessions, 6 baseline sessions with no operant conditioning (225 trials of surface electrical stimulation of the femoral nerve), followed by 24 training sessions (20 baseline trials followed by 225 trials with feedback of H-reflex magnitude). The investigators' main outcome measure was rectus femoris H-reflex magnitude. We also examined H-reflex magnitude of other quadriceps muscles.

Official Title
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Operant H-reflex Down-conditioning of Rectus Femoris in Post-stroke Stiff Knee Gait

Conditions
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Training

Intervention / Treatment
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* Behavioral: Operant RF H-reflex conditioning


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Premorbidly independent Mild to moderate impairment determined by standard practices per the physical therapist Ability to stand for 10-minute intervals unassisted Ability to walk for 10-minutes on a treadmill Reduced knee flexion during phase and SKG as determined by a clinician Hemiparesis Ability to provide informed consent Exclusion Criteria: History of cerebellar stroke, multiple stroke History of serious lower limb musculoskeletal injury Functionally relevant osteoarthritis and weight-bearing restrictions Have condition related to claustrophobia or other MRI contraindications Functionally relevant cognitive impairment Functionally relevant vision impairment Took antispasmodic medication one day prior to the session Had Botox injection one week prior to the session Pregnant women

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Training group<br>Participants receive 24 sessions of operant H-reflex conditioning of the rectus femoris. | Behavioral: Operant RF H-reflex conditioning<br>* Operant down-conditioning of rectus femoris H-reflex<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| RF H-reflex magnitude | H-reflex magnitude of rectus femoris | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| VM H-reflex magnitude | H-reflex magnitude of vastus medialis | 3 months |