Temporal Muscle-specific Disuse Atrophy during One Week of Leg Immobilization.

Autor:	Kilroe SP; Department of Sport and Health Sciences, College of Life and Environmental Science, University of Exeter, Exeter, UNITED KINGDOM., Fulford J; Peninsula NIHR Clinical Research Facility, College of Medicine and Health, University of Exeter, Exeter, UNITED KINGDOM., Jackman SR; Department of Sport and Health Sciences, College of Life and Environmental Science, University of Exeter, Exeter, UNITED KINGDOM., VAN Loon LJC; Department of Human Biology, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre, Maastricht, THE NETHERLANDS., Wall BT; Department of Sport and Health Sciences, College of Life and Environmental Science, University of Exeter, Exeter, UNITED KINGDOM.
Jazyk:	angličtina
Zdroj:	Medicine and science in sports and exercise [Med Sci Sports Exerc] 2020 Apr; Vol. 52 (4), pp. 944-954.
DOI:	10.1249/MSS.0000000000002200
Abstrakt:	Purpose: Musculoskeletal injuries necessitate periods of disuse (i.e., limb immobilization) during which rapid skeletal muscle atrophy occurs. The relative susceptibility of different muscles of the thigh to disuse atrophy remains uninvestigated. We assessed muscle disuse atrophy of individual thigh muscles throughout 1 wk of unilateral knee immobilization. Methods: Thirteen healthy, young (20.2 ± 0.6 yr) men underwent 7 d of unilateral leg immobilization via knee bracing. Magnetic resonance imaging scans were performed bilaterally prior to, and following 2 and 7 d of immobilization to determine the volume and anatomical cross-sectional area of the individual muscle groups of the upper legs. Results: In contrast to the control leg, total thigh muscle volume had decreased by 1.7% ± 0.3% (P < 0.01) and 5.5% ± 0.6% (P < 0.001) in the immobilized leg after 2 and 7 d of disuse, respectively. Muscle loss was significantly greater in the Musculus quadriceps (day 2; 1.7% ± 0.3% (P < 0.05) and day 7; 6.7% ± 0.6%) when compared with the Musculus hamstrings (day 2; 1.4% ± 0.2% (P < 0.01) and day 7; 3.5% ± 0.3%) after 7 d of disuse (P < 0.001). Individual muscles of the thigh exhibited different atrophy rates with the Musculus vastus lateralis anatomical cross-sectional area showing the greater (2.6% ± 0.4% and 7.2% ± 0.8%), and the Musculus gracilis the lesser (1.1% ± 0.7% and 2.3% ± 1.0%) decline following 2 and 7 d of immobilization, respectively (P < 0.01). Conclusions: Thigh muscle disuse atrophy occurs rapidly and is already evident within 2 d of leg immobilization and progresses at a similar rate over the next 5 d (~0.8% muscle loss per day). M. quadriceps muscle shows more atrophy when compared with the M. hamstrings.
Databáze:	MEDLINE
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