Changes in lower extremity muscle function after 56 days of bed rest
| Autor: | Joern Rittweger, Ulf Gast, Dieter Felsenberg, Ingo Michaelis, Bjoern Buehring, Daniel L. Belavý |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Adult
Male medicine.medical_specialty Time Factors Physiology medicine.medical_treatment Electromyography Isometric exercise medicine.disease_cause Bed rest Vibration Vertical jump Jumping Triceps surae muscle Germany Isometric Contraction Physiology (medical) Internal medicine medicine Humans Muscle Strength Muscle Skeletal Weightlessness Simulation Analysis of Variance Muscle Weakness medicine.diagnostic_test business.industry Muscle weakness Skeletal muscle Recovery of Function Biomechanical Phenomena Treatment Outcome medicine.anatomical_structure Lower Extremity Linear Models Cardiology Physical therapy medicine.symptom Weightlessness Countermeasures business Bed Rest |
| Zdroj: | Journal of Applied Physiology. 111:87-94 |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/japplphysiol.01294.2010 |
| Popis: | 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 muscle-function 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. |
| Databáze: | OpenAIRE |
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