Muscle Tone in Space (Myotones) - 09.19.18

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ISS Science for Everyone

Science Objectives for Everyone
The Muscle Tone in Space (Myotones) investigation observes the biochemical properties of muscles (e.g. muscle tone, stiffness, elasticity) during long-term exposure spaceflight environment. Results from this investigation can provide a better understanding of the principles of human resting muscle tone. This could lead to the development of new strategies for alternative treatments for rehabilitation on Earth, as well as for future space missions.
Science Results for Everyone
Information Pending

The following content was provided by Dieter Blottner, Ph.D., and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Erasmus Experiment Archive.
Experiment Details

OpNom: Myotones

Principal Investigator(s)
Dieter Blottner, Ph.D., Charité Universitätsmedizin Berlin Anatomy and Center of Space Medicine Berlin Neuromuscular Group, Berlin, Germany

Hanns-Christian Gunga, Ph.D., Charité,Center of Space Medicine Berlin, Berlin, Germany

Myoton AS, Tallinn, Estonia

Sponsoring Space Agency
European Space Agency (ESA)

Sponsoring Organization
European Space Agency

Research Benefits
Earth Benefits, Space Exploration

ISS Expedition Duration
September 2017 - April 2019; -

Expeditions Assigned

Previous Missions
Information Pending

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Experiment Description

Research Overview

The objectives of the Muscle Tone in Space (Myotones) investigation are:
  • To investigate the adaptation mechanisms related to the human resting myofascial system exposed to long-term continuous microgravity.
  • To gain a better, and more comprehensive, evaluation of the crew members performance control and fitness for variable mission duties (inflight monitoring).
  • To perform routine monitoring on crew members before launch (pre-flight training), and after landing (post-flight recovery).
  • To monitor, in relation to pre-flight data, the magnitude of changes throughout the full cycle of deconditioning on the International Space Station (ISS) and post-flight recovery.
  • To monitor on which level due to regular exercise the astronauts are able to maintain, and even up, the parameters measured by MyotonPRO on Earth vs. onboard the ISS.
  • To monitor the microgravity changes of different tissue and muscle types.


Based upon existing data on disuse-induced muscle atrophy, it is hypothesized that during spaceflight, muscle stiffness decreases, particularly in those muscles which are most important for postural support and movement (running, walking) (e.g. Soleus, Multifidus, vastus lateralis, paraspinal muscles of neck and back, hamstrings), whilst other phasic muscles (such as Gastrocnemius, Rectus abdominis, or shoulder and arm muscles) are relatively unaffected, thus serving as internal control. In addition, it is expected that exercise countermeasures performed inflight are able to either improve, or even to recover, myometric parameters. Thus, the new MyotonPRO technology could also assess effectiveness of countermeasure trials.
In particular, the hypotheses being tested in the Muscle Tone in Space (Myotones) investigation are as follows:
  • The biomechanical properties of the human myofascial system (state of tension stiffness, elasticity) significantly changes following microgravity unloading during short-medium or long duration spaceflight, with as yet unknown consequences for mission duty performance control.
  • Altered tone, viscoelasticity, and biomechanical properties of the human myofascial system in microgravity are reflected by changes in blood-borne biomarkers (e.g., matrix metalloproteinases) related to remodelling of connective tissue and extracellular matrix components. The key biomechanical properties recorded by the Myoton technology provides function-related data to better explain myofascial structure changes observed with ultrasound imaging, in particular tendon and fascia layers, before, during or after spaceflight.

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Space Applications
On Earth, the Human Resting Muscle Tone (HMRT), is an important, yet still not fully understood, biomechanical structure of the human movement apparatus supporting postural control, awareness of body position (proprioception) and muscle force production that altogether determine key biomechanical properties of muscle, tendon, and fascia such as tone (state of tension), elasticity, and stiffness. Furthermore, the proposed MyotonPRO experiment complements current onboard human health and fitness monitoring (e.g., heart rate, temperature, autonomic nervous system), by studying some key biomechanical properties (e.g. tone, stiffness, elasticity) critical for the neuromuscular status during spaceflight. The MyotonPRO experiment may also improve the science team’s understanding of the fundamental principles of the HRMT system on Earth, and in Space, that may also impact alternative treatments in neurorehabilitation in various clinical settings, in sedentary people and normal aging, as well as in future space missions.

Earth Applications
As part of the HRMT, the collagenous network fascial layers hosting numerous encapsulated mechanosensors and pain receptors (nociceptors) around groups of skeletal muscles (compartments) or intramuscular connective tissue layers, appear to be likely involved in more or less altered proprioception and pain sensation (nociception). Monitoring of the HRMT to understand the underlying mechanisms of deconditioning of the neuromuscular and myofascial system may also impact alternative treatments in neurorehabilitation in various clinical settings, in sedentary people and normal aging.

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Operational Requirements and Protocols

In-flight sessions (4 sessions during missions longer than 151 days) on:
1. FD 5-15 (Myoton only, early in-flight data sampling is strongly required due to monitoring of early microgravity adaptation)
2. FD 31-60 (Myoton/Ultrasound/1st in-flight blood sample)
3. FD 121-150 (Myoton only)
4. R-10 ± 5 days (Myoton/Ultrasound/2nd in-flight blood sample).

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Decadal Survey Recommendations

Information Pending

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Results/More Information

Information Pending

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Related Websites

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