Influence of Fast and Slow Imagined Muscle Contractions on Muscle Function or Central Nervous System Properties

Does the Speed of Imagined Muscle Contractions Affect Muscle Function and Central Nervous System Excitability?

The goal of this randomized clinical trial is to learn if imagining fast or slow muscle contractions causes different responses for nervous system excitability and muscle function in young, healthy males and females in. The main questions are:

Does imagining fast muscle contractions cause greater nervous system excitability compared to imagining slow muscle contractions?

Does imagining fast muscle contractions increase muscle function compared to imagining slow muscle contractions?

A control condition (rest) will be compared with two intervention conditions: imagining fast and imagining slow conditions, to determine if the fast and slow increase outcomes more than control and if fast has the greatest response.

Participants will:

• Attend 4 laboratory visits
• Perform 50 imagined contractions fast or slow, but with no physical movement
• Physical muscle contractions and non-invasive brain stimulation would be completed before and after each condition.

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Behavioral: Imagined muscle contractions

Detailed Description

Participants will complete 4 laboratory visits in a randomized order, including a familiarization session, a control condition, and 2 conditions involving imaginary muscle contractions. During visits involving imaginary muscle contractions, participants will complete 2 sets of 25 repetitions of either fast (i.e., less than 1 second to peak torque increase torque as fast as possible) or slow (i.e., 3 seconds to peak torque) isometric elbow flexions. Before and after each condition, single-pulse transcranial magnetic stimulation will be delivered to the primary motor cortex to measure the amplitude of motor-evoked potentials and the duration of the resulting silent periods in the bicep brachii to quantify changes in corticospinal excitability and inhibition, respectively. Rapid maximal voluntary isometric contractions will be used to measure changes in rate of torque development, peak torque, and rate of muscle activation.

• Study Type: Interventional
• Enrollment (Estimated): 18
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Garrett Hester, Ph.D.; Phone Number: 470-578-4267; Email: ghester4@kennesaw.edu

Study Locations

• United States
  • Georgia
    • Kennesaw, Georgia, United States, 30144
      • Recruiting
      • Kennesaw State University
      • Contact: Garrett Hester, Ph.D.; Phone Number: 470-578-4267; Email: ghester4@kennesaw.edu
      • Contact: Garrett Hester, Ph.D.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Be between the ages of 18 - 30
• Healthy (no medical conditions)
• If female, must be taking the same monophasic oral contraceptive for the past 6 months
• Have a body mass index between 18.5 - 30 kg/m2
• Have not performed structured cardiovascular or resistance exercise in past 3 years
• Be right-handed
• Not currently taking stimulants, antipsychotic, anxiety, or depression medications
• Have not suffered an upper extremity musculoskeletal injury within the past year

Exclusion Criteria:

• If transcranial magnetic stimulation (TMS) is not deemed appropriate depending on your responses to the TMS-specific questionnaire
• Being ambidextrous
• Although rare, you will be excluded if discernable muscle activation responses are not possible via TMS

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: Control; Participants will rest quietly with eyes closed during the control condition.
Experimental: Fast; Participants will imagine 2 blocks of 25 fast muscle contractions separated by 30 sec	Behavioral: Imagined muscle contractions; The intervention involved imagining, with no physical movement, of muscle contractions.
Experimental: Slow; Participants will imagine 2 blocks of 25 slow muscle contractions separated by 30 sec	Behavioral: Imagined muscle contractions; The intervention involved imagining, with no physical movement, of muscle contractions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in rate of torque development as measured by newton-meters per second	A measure of the capacity to increase muscle torque rapidly as determined by the slope of the torque-time curve	Baseline, minute 20
Change in nervous system excitability as measured by electromyographic waveform aplitude following motor cortex stimulation	A measure of excitability for the corticospinal tract	Baseline, minute 20

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in isometric bicep strength as measured by newton-meters of torque	Isometric strength of a muscle	Baseline, minute 20
Change in agonist muscle activation as measured by electromyography amplitude	A measure of the capacity at which the muscle is activated by the nervous system	Baseline, minute 20
Change in antagonist co-activation as measured by electromyography amplitude	A measure of the capacity at which the antagonist muscle is activated by the nervous system	Baseline, minute 20
Change in rate of agonist muscle activation as measured by electromyography amplitude	A measure of how quickly the nervous system activates the muscle	Baseline, minute 20
Change in nervous system inhibition as measured by electromyographic waveform aplitude following motor cortex stimulation	A measure of inhibition for the corticospinal tract	Baseline, minute 20

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Self-reported ability to imagine movements as measured by Movement Imagery Questionnaire-Revised as measured on a scale from 8 to 56	Survey that estimates one's capacity to imagine movement. A higher score indicates better imagination.	Baseline
Level of vividness for imagining the imagined contractions as measured by 7-point likert scale as measured from 1 to 7	A 7-point likert scale is used to to determine how vivid one's imagination was for the conditions. A higher score indicates greater difficulty imagining the movement.	20 minutes after baseline

Collaborators and Investigators

• Sponsor: Kennesaw State University

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2024
• Primary Completion (Estimated): May 1, 2025
• Study Completion (Estimated): May 1, 2025

Study Registration Dates

• First Submitted: October 2, 2024
• First Submitted That Met QC Criteria: October 3, 2024
• First Posted (Actual): October 4, 2024

Study Record Updates

• Last Update Posted (Estimated): October 9, 2024
• Last Update Submitted That Met QC Criteria: October 7, 2024
• Last Verified: October 1, 2024

More Information

Terms related to this study

• Keywords: Muscle strength; Nervous System; Motor Imagery
• Other Study ID Numbers: MI_KA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Non-identifying IPD will be provided upon a reasonable request.
• IPD Sharing Time Frame: Beginning 3 months and ending 5 years after the publication of results

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No