Abstract
Abstract
Purpose
The objective of this study was to assess whether artificial gravity attenuates any long-duration head-down 60 bed rest (HDBR)-induced alterations in motor unit (MU) properties.
Methods
Twenty-four healthy participants (16 men; 8 women; 26–54 years) underwent 60-day HDBR with (n = 16) or without (n = 8) 30 min artificial gravity daily induced by whole-body centrifugation. Compound muscle action potential (CMAP), MU number (MUNIX) and MU size (MUSIX) were estimated using the method of Motor Unit Number Index in the Abductor digiti minimi and tibialis anterior muscles 5 days before (BDC-5), and during day 4 (HDT4) and 59 (HDT59) of HDBR.
Results
The CMAP, MUNIX, and MUSIX at baseline did not change significantly in either muscle, irrespective of the intervention (p > 0.05). Across groups, there were no significant differences in any variable during HDBR, compared to BDC-5.
Conclusion
Sixty days of HDBR with or without artificial gravity does not induce alterations in motor unit number and size in the ADM or TA muscles in healthy individuals.
Funder
UK Space Agency
Deutsche Forschungsgemeinschaft
Deutsches Zentrum für Luft- und Raumfahrt
European Space Agency
National Aeronautics and Space Administration
Publisher
Springer Science and Business Media LLC
Subject
Physiology (medical),Public Health, Environmental and Occupational Health,Orthopedics and Sports Medicine,General Medicine,Public Health, Environmental and Occupational Health,Physiology
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