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

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.

Study Overview

• Status: Completed
• Conditions: Training
• Intervention / Treatment: Behavioral: Operant RF H-reflex conditioning

Detailed Description

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
• Enrollment (Actual): 7
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• United States
  • Texas
    • Austin, Texas, United States, 78712
      • University of Texas at Austin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	3 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	3 months

Collaborators and Investigators

• Sponsor: University of Texas at Austin
• Collaborators: Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)

Study record dates

Study Major Dates

• Study Start (Actual): July 28, 2018
• Primary Completion (Actual): February 17, 2020
• Study Completion (Actual): February 17, 2020

Study Registration Dates

• First Submitted: July 18, 2022
• First Submitted That Met QC Criteria: July 18, 2022
• First Posted (Actual): July 21, 2022

Study Record Updates

• Last Update Posted (Actual): July 16, 2024
• Last Update Submitted That Met QC Criteria: July 12, 2024
• Last Verified: July 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: 2018030053; R01HD100416 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Unidentified data available upon reasonable request
• IPD Sharing Time Frame: 3 years
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No