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

Early Phase 1CompletedNCT05467774

University of Texas at Austin7 enrolled

Overview

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.

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.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Training

Interventions

Operant RF H-reflex conditioningBEHAVIORAL

Operant down-conditioning of rectus femoris H-reflex

Eligibility

Sex: ALLMin age: 18 YearsMax age: 75 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Locations (1)

University of Texas at Austin

Austin, Texas, United States

Outcomes

Primary Outcomes

Percentage Change From Baseline in RF H-reflex Magnitude

H-reflex magnitude of rectus femoris. Lower values are considered better. The H-reflex is the amplitude of the monosynaptic spinal reflex, elicitied by electrical stimulation of the femoral nerve, normalized by the preceding M-wave. The M-wave is the amplitude of the muscle activity response to surface electrical stimulation of the femoral nerve. All muscle activity measured at the individual's rectus femoris of the stimulated limb. A value of 100% would mean no change in reflex magnitude, whereas a change of -20%, for instance, would mean a 20% drop in reflex magnitude over the 3 month training period.

Time frame: 3 months

Secondary Outcomes

Percentage Change From Baseline in VM H-reflex Magnitude

H-reflex magnitude of vastus medialis. Lower values are considered better. The H-reflex is the amplitude of the monosynaptic spinal reflex, elicitied by electrical stimulation of the femoral nerve, normalized by the preceding M-wave. The M-wave is the amplitude of the muscle activity response to surface electrical stimulation of the femoral nerve. All muscle activity measured at the individual's vastus medialis of the stimulated limb. A value of 100% would mean no change in reflex magnitude, whereas a change of -20%, for instance, would mean a 20% drop in reflex magnitude over the 3 month training period.

Time frame: 3 months

Data from ClinicalTrials.gov

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