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Muscular AtrophyiMOBNCT04199923

Mechanisms of Disuse Atrophy in Human Skeletal Muscle (iMOB)

A study testing Single leg immobilisation in people with Muscular Atrophy and Immobility Syndrome, run by University of Nottingham at 1 site in United Kingdom.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

Loss of muscle can be caused by a variety of stimuli and results in reduced mobility and strength and also impacts whole body health. Whilst it is known that muscles waste the process by which this occurs is not well understood. Read more about this study

Who is it for?
Ages 18 to 80 years, men onlyHealthy volunteers can take part
Conditions the study is for
Muscular Atrophy, Immobility Syndrome
What is being tested?
Single leg immobilisation
Could I receive a placebo?
No, everyone receives an active treatment
How many people
36 participants
Where
1 siteUnited Kingdom
Study dates
1 Apr 2019to 1 Oct 2026
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 80 years
  • Men only
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • Group 1 and 2: Male, Age 18-40, BMI 18-35
  • Group 3: Male, Age 65-80, BMI 18-35

Who cannot join

  • BMI > 35 / <18
  • Female
  • Personal or Family History of Venous Thromboembolism
  • Significant medical comorbidities

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • Graduate Entry Medical School

    Derby, Derbyshire, DE22 3DT

Other trials in United Kingdom

About this study

Official title: Harnessing Muscle-specific Atrophy Susceptibility to Disentangle the Mechanisms of Disuse Atrophy in Human Skeletal Muscle Atrophy (iMOB)

Loss of muscle can be caused by a variety of stimuli and results in reduced mobility and strength and also impacts whole body health. Whilst it is known that muscles waste the process by which this occurs is not well understood. Furthermore, whilst some muscles waste quickly others seem resistant to the effects of disuse.

This study aims to evaluate how quickly changes in muscles start to occur, and investigate the processes which underlie muscle atrophy. By studying muscles which waste quickly and those which are resistant to atrophy this study aims to identify the different processes which lead to muscle loss. This study will also evaluate the differences in muscle changes between young and old people.

Read the detailed description

Skeletal muscles host ~40% of all protein in the body. Muscles are not only crucial for locomotion but also represent the body's largest metabolically active tissue, glucose disposal site and fuel reservoir for other organs in pathological conditions (i.e., supply of amino acids to the liver for gluconeogenesis). Muscle atrophy is characterized by a reduction in cross sectional area (CSA) and length and occurs in many common illnesses (e.g. cancers (1), renal/heart failure, sepsis, genetic diseases, neurodegenerative disorders etc). It is also prevalent in situations of reduced neural input such as leg casting after fractures (2), bed-rest, spinal cord injury (3), space flight and chronic physical inactivity. Atrophy results in a loss of muscle power and strength (which is related to increased morbidity and mortality (4)) and reduced capacities for whole-body glucose storage and metabolism which causes insulin resistance. Strategies to oppose atrophy are limited but include mechanical loading (5) and the synergistic anabolic effects of nutrients. Although muscle atrophy is of great clinical importance, relatively little mechanistic research has been done in humans. Thus, the aim of this study is to assess the link between the variation in muscle physiological responses to disuse atrophy with variation in protein turnover and molecular-networks. This will not only provide new hypotheses for physiological regulation of human muscle and generate 'intervention targets' derived from clinically relevant human studies, it will also improve understanding of whether the response to disuse is altered with age and determine if mechanistic differences in atrophy resistant and atrophy sensitive muscles might explain inter-muscular variation in susceptibility to atrophy.

This study aims to define the molecular and metabolic mechanisms causing disuse atrophy in both young and older individuals and explore how and why some muscles are protected against it. The study will also assess temporal aspects of disuse atrophy (in younger individuals only) to explore the mechanistic basis for the more rapid atrophy observed in the early days of disuse.

Being tested
Single leg immobilisation
Medical subject headings
Muscular Atrophy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Single leg immobilisationBehavioural

    Immobilisation with single leg suspension immobilisation

Study groups in NCT04199923
Study groupRoleWhat they receive
15 Day immobilisationExperimentalThe dominant leg of young healthy patients (18-40 years without serious comorbidities) will be immobilised using a fixed knee brace and aircast boot for 15 continuous days
Receives: Behavioral: Single leg immobilisation
5 Day immobilisation youngExperimentalThe dominant leg of young healthy patients (18-40 years without serious comorbidities) will be immobilised using a fixed knee brace and aircast boot for 5 continuous days
Receives: Behavioral: Single leg immobilisation
5 Day immobilisation oldExperimentalThe dominant leg of aged patients (65-80 years without serious comorbidities) will be immobilised using a fixed knee brace and aircast boot for 5 continuous days
Receives: Behavioral: Single leg immobilisation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Changes in muscle volume (cm3)

    MRI assessment of muscle volume in Tibialis Anterior (TA) and Medial Gastrocnemius (MG) in immobilised vs non-immobilised leg, pre and post immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  2. Changes in muscle thickness (cm)

    Ultrasound scan (USS) assessment of muscle thickness in Tibialis Anterior (TA) and Medial Gastrocnemius (MG) in immobilised vs non-immobilised leg, pre and post immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  3. Changes in muscle cross surface area (cm2)

    Ultrasound assessment of muscle cross surface area, in tibialis anterior (TA) and Medial Gastrocnemius (MG) in immobilised vs non-immobilised pre and post immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  4. Changes in muscle fibre length (cm)

    Ultrasound assessment of muscle fibre length in tibialis anterior (TA) and Medial Gastrocnemius (MG) in immobilised vs non-immobilised pre and post immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  5. Changes in muscle fibre pennation angle (degrees)

    Ultrasound assessment of muscle fibre pennation angle in tibialis anterior (TA) and Medial Gastrocnemius (MG) in immobilised vs non-immobilised pre and post immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  6. Muscle Protein Synthesis (MPS) rate (%/hr)

    IV tracer (Individual muscle MPS in TA+MG muscles in immobilised vs non immobilised legs)

    Measured: Over 8 hours following immobilisation period

  7. Muscle Protein Breakdown (MPB) rate (%/hr)

    IV Pulse tracers (IV tracers to give muscle specific MPB measures of TA+MG muscles in immobilised vs non-immobilised legs)

    Measured: Over 8 hours following immobilisation period

Secondary outcomes (10)
  1. Muscle blood flow

    contrast enhanced ultrasound (CEUS) assessment of muscle blood flow in immobilised vs non-immobilised legs (TA+MG muscle specific)

    Measured: over 5 minutes (following immobilisation period)

  2. Leg blood flow

    Doppler assessment of leg blood flow through common femoral artery in fed and fasted states in both immobilised and non-immobilised leg

    Measured: Over 5 minutes (following immobilisation period)

  3. Anabolic Signalling

    Measurement of anabolic signalling pathways by western blot (comparison between immobilised vs non immobilised TA + MG muscles)

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  4. Catabolic Signaling

    Measurement of proteasome and lysosomal and related catabolic signalling pathways by western blot (comparison between immobilised vs non immobilised TA + MG muscles)

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  5. RNA sequencing

    complete RNA sequencing of immobilised vs non immobilised TA + MG muscles to determine gene set enrichment and pathway analysis

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  6. Histology

    Morphological assessment of muscle fibres by histological techniques (comparing immobilised vs non immobilised TA + MG muscles)

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  7. Mitochondrial respiration

    Measurement of mitochondrial respiration to assess different complex activity in immobilised vs non-immobilised TA + MG muscles

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  8. Intramuscular electromyography (iEMG)

    Electrically induced maximum force development and fatigability in TA + MG muscles pre and post immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  9. Muscle power

    Assessment of changes in muscle power secondary to immobilisation through 1 rep max (kg) pre and post immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

  10. Cardio pulmonary fitness

    Cardiopulmonary Exercise Testing (CPET) to assess changes in aerobic fitness (V02 max, anaerobic threshold and Watt Max) following immobilisation

    Measured: 14 days in group 1. 5 days in groups 2 and 3

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Dec 2019
  2. Study start1 Apr 2019
  3. Primary completion1 Jul 2026 (estimated)
  4. Study completion1 Oct 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Non-randomised
Intervention model
Single group
Model description
unilateral limb immobilisation study
Masking
None (open label)
Enrolment
36 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT04199923
Sponsor's protocol ID
1031809
Acronym
iMOB
Status last verified
Apr 2025
First submitted
26 Nov 2019
Last updated
2 May 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Single leg immobilisation in people with Muscular Atrophy and Immobility Syndrome, run by University of Nottingham at 1 site in United Kingdom.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 2 May 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in muscle volume (cm3) (time frame: 14 days in group 1. 5 days in groups 2 and 3). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 May 2025.

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