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Changes in lower extremity muscle function after 56 days of bed rest

Buehring, Björn and Belavy, Daniel and Michaelis, Ingo and Gast, Ulf and Felsenberg, Dieter and Rittwger, Jörn (2011) Changes in lower extremity muscle function after 56 days of bed rest. Journal of Applied Physiology, 111, pp. 87-94.

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Preservation of muscle function, known to decline in microgravity and simulation (bed rest), is important for successful spaceflight missions. Hence, there is great interest in developing interventions to prevent musclefunction loss. In this study, 20 males underwent 56 days of bed rest. Ten volunteers were randomized to do resistive vibration exercise (RVE). The other 10 served as controls. RVE consisted of muscle contractions against resistance and concurrent whole-body vibration. Main outcome parameters were maximal isometric plantar-flexion force (IPFF), electromyography (EMG)/force ratio, as well as jumping power and height. Measurements were obtained before and after bed rest, including a morning and evening assessment on the first day of recovery from bed rest. IPFF (-17.1%), jumping peak power (-24.1%), and height (-28.5%) declined (P < 0.05) in the control group. There was a trend to EMG/force ratio decrease (-20%; P < 0.051). RVE preserved IPFF and mitigated the decline of countermovement jump performance (peak power -12.2%; height -14.2%). In both groups, IPFF was reduced between the two measurements of the first day of reambulation. This study indicates that bed rest and countermeasure exercises differentially affect the various functions of skeletal muscle. Moreover, the time course during recovery needs to be considered more thoroughly in future studies, as IPFF declined not only with bed rest but also within the first day of reambulation. RVE was effective in maintaining IPFF but only mitigated the decline in jumping performance. More research is needed to develop countermeasures that maintain muscle strength as well as other muscle functions including power.

Document Type:Article
Title:Changes in lower extremity muscle function after 56 days of bed rest
AuthorsInstitution or Email of Authors
Buehring, BjörnCharité University Medicine Berlin
Belavy, DanielCharité University Medicine Berlin
Michaelis, IngoCharité University Medicine Berlin
Gast, UlfCharité University Medicine Berlin
Felsenberg, DieterCharité University Medicine Berlin
Rittwger, Jörnjoern.rittweger@dlr.de
Journal or Publication Title:Journal of Applied Physiology
Refereed publication:Yes
In ISI Web of Science:Yes
Page Range:pp. 87-94
Keywords:jump mechanography; muscle power; muscle force; E
HGF - Research field:Aeronautics, Space and Transport (old)
HGF - Program:Space (old)
HGF - Program Themes:W FR - Forschung unter Weltraumbedingungen (old)
DLR - Research area:Space
DLR - Program:W FR - Forschung unter Weltraumbedingungen
DLR - Research theme (Project):W - Vorhaben Beschleunigungsinduzierte Effekte (old)
Location: Köln-Porz
Institutes and Institutions:Institute of Aerospace Medicine > Space Physiology
Deposited By: Jörn Rittweger
Deposited On:09 Sep 2011 09:19
Last Modified:12 Dec 2013 21:20

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