The Effect of Altered Gravity Condition on Postural Control

Study Overview
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Brief Summary
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The scientific goal of this experiment is to evaluate changes in balance control in response to microgravity during reactive balance tasks. For that purpose, kinematic and neuromuscular parameters under microgravity are compared to normal gravity conditions. To induce postural responses among the test subjects, an electromagnetic maneuverable postural platform will be used in order to randomly elicit perturbations. Postural reactions will be quantified by means of mechanical and electromyographic data. In Addition, peripheral nerve stimulation will be used to assess the spinal excitability by means of H-reflex recordings. H-reflex measurements were chosen as they allow reliable information about inhibitory and facilitatory mechanisms taking place at the spinal level.

Conditions
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Healthy

Intervention / Treatment
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* Other: Parabolic flight
* Other: balance control measurements
* Device: electromagnetic maneuverable postural platform


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteers (men or women) Aged from 21 to 65 Affiliated to a Social Security system and, for non-French resident, holding a European Health Insurance Card (EHIC) Who accepted to take part in the study Who have given their written stated consent Who has passed a medical examination similar to a standard aviation medical examination for private pilot aptitude. There will be no additional test performed for subject selection. Exclusion Criteria: Person who took part in a previous biomedical research protocol, of which exclusion period is not terminated Person with medical history of neurological disorders Person with medical history of musculoskeletal disorders of the lower limbs, especially of the ankle and knee joint. Pregnant women

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: in balance control in response to microgravity<br>to evaluate changes in balance control in response to microgravity during reactive balance tasks compared to normal gravity. | Other: Parabolic flight<br> <br> Other: balance control measurements<br> <br> Device: electromagnetic maneuverable postural platform<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| balance skill, expressed by the postural sway in mm |  | baseline | 
| neuromuscular activity, expressed by the Electromyograpy (EMG)-amplitudes |  | baseline | 
| spinal excitability, expressed by H-Reflexes |  | baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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volunteers