Brain and Muscle Plasticity During Immobilization

Examining Changes in Muscle Size and Strength, Neuromuscular Function, and Brain Plasticity During Limb Immobilization in Women

Patients in rehabilitation may undergo periods of prolonged limb immobilization in response to injury, surgery, or illness. Due to disuse, the size and strength of muscles controlling the affected limb can decrease significantly, possibly resulting in physical impairment or lower quality of life during the recovery phase. Prior immobilization studies have shown that the rate and degree of decline in muscle strength exceeds that of muscle size, indicating that determinants of muscle strength unrelated to muscle size may further contribute to functional changes during immobilization.

The purpose of this study is to describe the changes in muscle strength, muscle size, corticospinal excitability, voluntary activation, M1 cortical thickness, and resting state functional connectivity following a 2-week limb immobilization period in young women.

Study Overview

• Status: Completed
• Conditions: Muscle Atrophy
• Intervention / Treatment: Behavioral: Immobilization

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H2W 1S4
      • Exercise Metabolism and Nutrition Research Laboratory

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

• Biologically female
• Right-hand dominant
• Body mass index between 18.5-30 kg/m^2 (inclusive)
• Regular menstrual cycle
• Be able to maintain a habitual diet throughout the duration of the study

Exclusion Criteria:

• Use of tobacco
• Pregnancy
• A history of brain trauma
• Suffers from a neurological disease or movement disorder
• Peripheral nerve damage
• Use of medications known to affect protein metabolism (i.e., corticosteroids, non-steroidal anti-inflammatory drugs, or prescription strength acne medications)
• Diagnosed with or suspects having a psychiatric illness
• Use of dietary supplements known to affect muscle size (i.e., creatine, fish oil)
• Past or present diagnosis of an eating disorder by a physician or registered dietician
• Possesses any metal implants (e.g. artificial joints, pacemakers, stents) or non-removeable medical devices that are contraindicative for magnetic resonance imaging (e.g. insulin pumps)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: NON_RANDOMIZED
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: Immobilized arm; Left arm of participant	Behavioral: Immobilization; Immobilization of left arm using a brace and sling.
NO_INTERVENTION: Non-immobilized arm; Right arm of participant

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in isometric elbow flexion and extension peak torque, both arms	Measured using an isokinetic dynamometer; peak torque during static contraction of the elbow flexors and extensors	Comparison between before and after 2 weeks of left arm immobilization
Change in isokinetic elbow flexion and extension peak torque, both arms	Measured using an isokinetic dynamometer; peak torque during dynamic contraction of the elbow flexors and extensors	Comparison between before and after 2 weeks of left arm immobilization
Change in cross-sectional area of the elbow flexor and extensor muscles, both arms	Obtained from magnetic resonance images of each arm	Comparison between before and after 2 weeks of left arm immobilization
Change in volume of the elbow flexor and extensor muscles, both arms	Obtained from magnetic resonance images of each arm	Comparison between before and after 2 weeks of left arm immobilization
Voluntary activation of biceps brachii, both arms	Measured using peripheral nerve stimulation and an isokinetic dynamometer; estimation of the capacity to voluntarily activate the force-generating elements of the biceps brachii during maximal effort elbow flexion	Comparison between before and after 2 weeks of left arm immobilization
Change in corticospinal excitability of biceps brachii, both arms	Measured using transcranial magnetic stimulation; estimation of the efficacy of the corticospinal tract to relay electrical signals to the biceps brachii muscle	Comparison between before immobilization and 24 hours of left arm immobilization, and before and after 2 weeks of left arm immobilization

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in right and left primary motor cortex thickness	Obtained from magnetic resonance image of the brain	Comparison between before and after 2 weeks of left arm immobilization
Change in whole brain resting state functional connectivity	Obtained from magnetic resonance image of the brain	Comparison between before and after 2 weeks of left arm immobilization

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
2-day caloric and macronutrient intake, before immobilization	Obtained using self-reported dietary intake records	Measured during the 2-day period right before left arm immobilization
2-day caloric and macronutrient intake, during immobilization	Obtained using self-reported dietary intake records	Measured during the last 2 days of left arm immobilization
Ovarian hormone concentrations (estradiol, progesterone)	Obtained using blood samples	Measured on day of left arm immobilization, before putting on the arm brace
Ovarian hormone concentrations (estradiol, progesterone)	Obtained using blood samples	Measured after 2 weeks of left arm immobilization

Collaborators and Investigators

• Sponsor: McGill University

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 8, 2021
• Primary Completion (ACTUAL): April 21, 2022
• Study Completion (ACTUAL): April 21, 2022

Study Registration Dates

• First Submitted: October 10, 2021
• First Submitted That Met QC Criteria: November 1, 2021
• First Posted (ACTUAL): November 10, 2021

Study Record Updates

• Last Update Posted (ACTUAL): May 19, 2022
• Last Update Submitted That Met QC Criteria: May 17, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Nervous System Diseases; Neurologic Manifestations; Neuromuscular Manifestations; Pathological Conditions, Anatomical; Atrophy; Muscular Atrophy
• Other Study ID Numbers: A00-M01-21A

Drug and device information, study documents

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