Imagined Muscle Contractions for Healthy Individuals

Overseen By Garrett Hester, Ph.D.

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: Kennesaw State University

Must be taking: Monophasic contraceptives

Must not be taking: Stimulants, antipsychotic, anxiety, depression

Disqualifiers: Ambidextrous, musculoskeletal injury, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 5

18 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores how imagining muscle movements affects nerve and muscle activity. It compares the effects of imagining fast versus slow muscle movements to determine which enhances nerve excitability and muscle function more effectively. Participants will either rest quietly or imagine performing muscle contractions (referred to as Imagined Muscle Contractions) without actual movement. This trial may suit healthy young adults who have not engaged in structured exercise in the past three years and can imagine muscle movements without any physical injury. As an unphased trial, this study provides a unique opportunity to contribute to the scientific understanding of mind-muscle connections.

Will I have to stop taking my current medications?

The trial requires that you are not currently taking stimulants, antipsychotic, anxiety, or depression medications. If you are on these medications, you would need to stop taking them to participate.

What prior data suggests that imagined muscle contractions are safe for healthy individuals?

Research has shown that imagining muscle movements is generally safe. Studies have found that combining mental effort with light muscle exercises can safely strengthen muscles, even in individuals at higher risk. In this trial, participants will imagine moving their muscles without actual movement. Previous studies have linked this type of mental exercise to increased strength without causing physical strain or injury.

Because there is no physical movement, the risk of injury remains low, making it a safe option for most people. Overall, evidence suggests that imagining muscle movements is a safe and non-invasive method to potentially improve muscle function. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the trial of imagined muscle contractions because it explores the power of the mind in enhancing physical performance without actual physical movement. Unlike traditional physical therapies that require active muscle engagement, this method investigates whether simply imagining muscle contractions can produce similar benefits, potentially offering a new avenue for rehabilitation or athletic training. By examining both fast and slow imagined contractions, the study seeks to uncover how different mental visualizations might influence muscle strength and coordination, offering insights into harnessing mental practices for physical health improvements.

What evidence suggests that imagined muscle contractions are effective for nervous system excitability and muscle function?

Research has shown that imagining muscle movements can strengthen muscles. One study found that simply thinking about strong muscle movements improved muscle strength without physical exercise. Another study demonstrated a 22% increase in muscle strength after participants used mental imagery of movements for eight weeks. These findings suggest that imagining muscle movements, whether fast or slow, can enhance muscle function and activate the nervous system. In this trial, participants will either imagine fast or slow muscle contractions or rest quietly as part of the control condition. Imagining these movements might be nearly as effective as performing the exercises. ^{3 6 7 8 9}

Are You a Good Fit for This Trial?

This trial is for right-handed individuals aged 18-30, with a BMI of 18.5-30 kg/m2, who are healthy and haven't done structured exercise in the last 3 years. Women must have been on the same oral contraceptive for 6 months. Participants should not be taking certain medications or have had recent musculoskeletal injuries.

Inclusion Criteria

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

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

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Familiarization

Participants attend a familiarization session to understand the trial procedures

1 visit

1 visit (in-person)

Intervention

Participants complete 4 laboratory visits including a control condition and 2 conditions involving imagined muscle contractions

4 visits

4 visits (in-person)

Follow-up

Participants are monitored for changes in muscle function and nervous system excitability

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Imagined Muscle Contractions

Trial Overview

The study tests if imagining fast versus slow muscle contractions affects nervous system excitability and muscle function differently in young adults. It involves four lab visits where participants imagine doing these contractions without moving, before and after which their muscles and brain responses are measured.

How Is the Trial Designed?

Group I: Slow Experimental Treatment 1 Intervention

Participants will imagine 2 blocks of 25 slow muscle contractions separated by 30 sec

Group II: Fast Experimental Treatment 1 Intervention

Participants will imagine 2 blocks of 25 fast muscle contractions separated by 30 sec

Group III: Control Active Control 1 Intervention

Participants will rest quietly with eyes closed during the control condition.

Who Is Running the Clinical Trial?

Kennesaw State University

Lead Sponsor

Trials

14

Recruited

860+

Published Research Related to This Trial

Gait imagery (GI) significantly reduces muscle activity in the tibialis anterior (TA) muscle during imagined walking tasks, particularly after actual walking experience, indicating a potential neural mechanism at play.

The study involved 36 healthy young individuals and found that the difficulty of imagining walking improved after actual walking, suggesting that previous experience enhances the effectiveness of GI in influencing muscle activity.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

How Posture and Previous Sensorimotor Experience Influence Muscle Activity during Gait Imagery in Young Healthy Individuals. Kolářová, B., Tomsa, M., Kolář, P., et al.[2023]

In a study with 19 participants, it was found that imagining wrist movements can influence the perception of kinesthetic illusions caused by tendon vibration, demonstrating a connection between motor imagery and sensory perception.

The research showed that motor imagery can modulate muscle activity, with wrist extension imagery reducing the perceived angle of illusory flexion while increasing extensor muscle activity, indicating that both imagery and illusion share common neural pathways but operate through different physiological mechanisms.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Perceptual changes in illusory wrist flexion angles resulting from motor imagery of the same wrist movements. Kitada, R., Naito, E., Matsumura, M.[2019]

Mental training using maximal imagined contractions (MIC) does not lead to neuromuscular fatigue, unlike physical training with maximal voluntary contractions (MVC), which causes a significant drop in muscle strength.

Combining mental training (MIC) with physical training (MVC) allows for increased overall workload without additional fatigue, suggesting that motor imagery can be a beneficial supplement to physical practice.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Does a mental training session induce neuromuscular fatigue? Rozand, V., Lebon, F., Papaxanthis, C., et al.[2014]

Motor imagery (MI) can influence the initiation of muscle contraction, as evidenced by a shorter delay time in muscle response during MI compared to control conditions, suggesting that MI affects how quickly muscles are activated.

However, MI does not alter the actual contraction characteristics, such as velocity and maximal displacement, indicating that while MI impacts the brain's command to move, it does not change how the muscles contract once activated.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Motor imagery and the muscle system. Wieland, B., Behringer, M., Zentgraf, K.[2022]

In a study involving 10 right-handed subjects, both executed and imagined movements of the hands activated similar brain regions, including the supplementary motor area, premotor cortex, and primary motor cortex, suggesting that motor imagery and actual movement share common neural pathways.

The cerebellum showed different activation patterns during imagined versus executed movements, indicating that while the anterior lobe is more active during actual movement, the posterior cerebellum may play a role in inhibiting movement during imagination.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Activation of cortical and cerebellar motor areas during executed and imagined hand movements: an fMRI study. Lotze, M., Montoya, P., Erb, M., et al.[2022]

The study found that during mental simulation of movements, the slow motor pathways show task-specific activation, with reduced activation for imagined ballistic contractions and enhanced activation for imagined tonic contractions, similar to real movements.

This suggests that motor imagery activates distinct subsets of neurons in the primary motor cortex in a way that mirrors actual muscle contractions, indicating a complex relationship between imagined and real movements.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery. Keller, M., Taube, W., Lauber, B.[2019]

Mental imagery (MI) has the potential to positively influence fascial tissue, which has been largely overlooked in previous research focused on muscle and neural tissues.

Fascial mental imagery (FMI), particularly through methods like fascial dynamic neuro-cognitive imagery (FDNI), could be beneficial for rehabilitation and prevention of conditions related to fascia, enhancing proprioception and cognitive functions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Integrating mental imagery and fascial tissue: A conceptualization for research into movement and cognition. Abraham, A., Franklin, E., Stecco, C., et al.[2020]

Combining mental imagery with physical practice can enhance strength performance, and mental imagery alone can help prevent strength loss during short-term immobilization, such as after ACL injuries.

Internal mental imagery is significantly more effective for improving muscle strength than external imagery, with effects mediated by factors like motivation and self-efficacy, and linked to neural adaptations and increased muscle activation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effects of Mental Imagery on Muscular Strength in Healthy and Patient Participants: A Systematic Review. Slimani, M., Tod, D., Chaabene, H., et al.[2019]

Imagined motor movement activates similar brain regions as actual movement, as shown by increased gamma band activity (GBA) in a study of 56 healthy male subjects, indicating heightened cognitive activity during both types of movements.

The study found no significant difference in GBA between real and imagined movements, suggesting that motor imagery could be an effective alternative to physical movement for enhancing performance, potentially useful in rehabilitation through techniques like mirror therapy.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparison of Spectral Analysis of Gamma Band Activity During Actual and Imagined Movements as a Cognitive Tool. Kumawat, J., Yadav, A., Yadav, K., et al.[2023]

Using fMRI, the study found that imagining different levels of force during hand grasping activates specific brain regions, including the dorsolateral prefrontal cortex and supplementary motor area, indicating a clear relationship between imagined force and brain activity.

The intensity of brain activation increased with higher imagined force levels, suggesting that it may be possible to decode the intended force level from brain activity during motor imagery, which could have implications for rehabilitation in patients.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Activity of right premotor-parietal regions dependent upon imagined force level: an fMRI study. Mizuguchi, N., Nakata, H., Kanosue, K.[2020]

Prolonged motor imagery (MI) can lead to increased mental fatigue, which negatively affects the perceived effort and performance of subsequent physical exercises, as shown in a study with 13 participants who performed imagined and actual knee extensions.

The study found that as mental fatigue increased during MI, there was a corresponding rise in motor-related cortical potential amplitude and perceived effort, indicating that prolonged MI may impair the motor commands necessary for both imagined and actual muscle contractions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mental fatigue induced by prolonged motor imagery increases perception of effort and the activity of motor areas. Jacquet, T., Lepers, R., Poulin-Charronnat, B., et al.[2021]

In a study with 12 healthy subjects, F-wave persistence significantly increased during motor imagery and minimal muscle contraction, indicating that these techniques can enhance nerve signal recording.

The results suggest that instructing patients to perform minimal muscle contractions can improve F-wave recording efficacy, as F-wave persistence peaked at 3% of maximal voluntary contraction before decreasing with higher effort levels.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of motor imagery and voluntary muscle contraction on the F wave. Hara, M., Kimura, J., Walker, DD., et al.[2010]

The study offers a mathematical framework to explain the 'let-go' phenomenon, where individuals involuntarily release objects when exposed to electrical stimulation, particularly affecting forearm muscles.

It highlights the importance of various factors, including electrophysiological and anthropometric characteristics, in understanding how accidental electrical stimulation impacts muscle control.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A theoretical analysis of the "let-go" phenomenon. Sweeney, JD.[2019]

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