20.500.12556/DiRROS-31972 Alterations in muscle contractile properties, structure, and function during 10-d bed rest, postrecovery, and after COVID-19 lockdown We aimed to identify early tensiomyography alterations in six muscles during a 10-d bed rest (BR10), followed by a 30-d recovery period (R+30), and to compare these changes with those observed after the 50-d COVID-19 lockdown in 10 healthy males (22.9 ± 5.0 yr). Methods: Tensiomyography and muscle thickness (assessed by ultrasound imaging) were assessed at baseline, during bed rest, at BR10, R+30, and after the COVID-19 lockdown. Additional assessments included vertical jump performance (force plate), body composition (bioimpedance), physical activity (Global Physical Activity Questionnaire), and lower back pain (VAS). Results: By BR10, participants experienced a 1.9% body mass loss, a 3.8% increase in fat mass, and a 2.4% reduction in muscle mass. Although anthropometric parameters returned to baseline by R+30, fat mass increased again by 3.9% postlockdown. Jump height declined by 10.1% at BR10, returned to baseline at R+30, and remained stable thereafter. Muscle thickness decreased by 7.0% in the vastus lateralis at BR10 and by 10.1% postlockdown. Tensiomyographic amplitude increased in five leg muscles before BR10, recovered at R+30 and increased again after postlockdown, whereas a reduction was observed in the erector spinae within the first 48 h, coinciding with reported lower back pain. In the erector spinae, both delay and contraction time decreased during BR10 and postlockdown, whereas contraction time of the biceps femoris increased before BR10 and remained elevated postlockdown. Conclusions: The observed post COVID-19 lockdown alterations in tensiomyographic parameters followed the same trend as those induced by bed rest, albeit with smaller magnitude. These findings support the utility of TMG as a sensitive and noninvasive method for monitoring muscle responses across different disuse paradigms. atrophy disuse skeletal muscle tensiomyography ultrasound atrofija neuporaba skeletna mišica tenziomiografija ultrazvok true false true Angleški jezik Slovenski jezik Copyright © 2026 The Author(s) Neznano 2026-08-21 10:09:39 2026-08-21 10:09:40 2026-08-22 03:49:53 0000-00-00 00:00:00 2026 0 0 Nasl. z nasl. zaslona; Opis vira z dne 21. 8. 2026; str. 1674-1686 no. 8 Vol. 58 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2026-01-01 796.01:612 1530-0315 10.1249/MSS.0000000000003986 288421891 26-08-21-288421891-101-Simunic.pdf 26-08-21-288421891-101-Simunic.pdf 1 ED64883857053423969618274700E0A0 2c946b9af5aaa86cceb850d9a2b18834c3509c6cfb9c804f1e83d4bae2cea785 44792520-9d38-11f1-af5a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=49783 https://www.ovid.com/jnls/acsm-msse/fulltext/10.1249/mss.0000000000003986~alterations-in-muscle-contractile-properties-structure-and 0 316c7eed-9d38-11f1-af5a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=49782 http://hdl.handle.net/20.500.12556/DiRROS-22783 0 6089fab6-9d38-11f1-af5a-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=49784 Znanstveno-raziskovalno središče Koper / Centro di Ricerche Scientifiche Capodistria 0 0 0