Healthy
Conditions
Keywords
Muscle strength, Nervous System, Motor Imagery
Brief summary
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.
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.
Interventions
BEHAVIORALImagined muscle contractions
The intervention involved imagining, with no physical movement, of muscle contractions.
Sponsors
Kennesaw State University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in nervous system excitability as measured by electromyographic waveform aplitude following motor cortex stimulation | Baseline, minute 20 | A measure of excitability for the corticospinal tract |
| Change in rate of torque development as measured by newton-meters per second | Baseline, minute 20 | A measure of the capacity to increase muscle torque rapidly as determined by the slope of the torque-time curve |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in agonist muscle activation as measured by electromyography amplitude | Baseline, minute 20 | A measure of the capacity at which the muscle is activated by the nervous system |
| Change in rate of agonist muscle activation as measured by electromyography amplitude | Baseline, minute 20 | A measure of how quickly the nervous system activates the muscle |
| Change in nervous system inhibition as measured by electromyographic waveform aplitude following motor cortex stimulation | Baseline, minute 20 | A measure of inhibition for the corticospinal tract |
| Change in antagonist co-activation as measured by electromyography amplitude | Baseline, minute 20 | A measure of the capacity at which the antagonist muscle is activated by the nervous system |
| Change in isometric bicep strength as measured by newton-meters of torque | Baseline, minute 20 | Isometric strength of a muscle |
Other
| Measure | Time frame | Description |
|---|---|---|
| Self-reported ability to imagine movements as measured by Movement Imagery Questionnaire-Revised as measured on a scale from 8 to 56 | Baseline | Survey that estimates one's capacity to imagine movement. A higher score indicates better imagination. |
| Level of vividness for imagining the imagined contractions as measured by 7-point likert scale as measured from 1 to 7 | 20 minutes after baseline | 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. |
Countries
United States
Contacts
Primary ContactGarrett Hester, Ph.D.
Outcome results
None listed