Ferreira Leandro Gomes de Jesus, da Silva Almeida Isabella, Costa Rochelle Rocha, Roriz Gabrielle Vieira, Geremia Jeam Marcel, Durigan João Luiz Quagliotti, Marqueti Rita de Cássia
Laboratory of Muscle and Tendon Plasticity, Graduate Program in Rehabilitation Science, Faculdade de Ciências e Tecnologias em Saúde, Universidade de Brasília, Brasília, Brazil.
Laboratory of Molecular Analysis, Graduate Program in Rehabilitation Science, Faculdade de Ciências e Tecnologias em Saúde, Universidade de Brasília, Brasília, Brazil.
Front Physiol. 2025 Aug 25;16:1641046. doi: 10.3389/fphys.2025.1641046. eCollection 2025.
There are limited studies on the long-term effects of COVID-19 on skeletal muscle morphology and architecture. Therefore, this study aims to address this gap by assessing the effects of prior COVID-19 infection on quadriceps muscle architecture and tendon-aponeurosis complex (TAC) properties over a one-year period, comparing three cohorts: individuals with moderate COVID-19, individuals with severe COVID-19, and a healthy control group.
Seventy participants were included in the study and allocated to three groups: moderate COVID-19 (n = 22), severe COVID-19 (n = 18), and control (n = 30). Four assessments were conducted over 1 year for the COVID groups. Maximal voluntary isometric (MVIC) knee extension contractions were performed on an isometric dynamometer, with simultaneous ultrasound imaging of the vastus lateralis (VL) and rectus femoris (RF) muscles. Fascicle length (FL) and pennation angle (PA) were obtained at rest and during MVIC, along with TAC displacement. Generalized Estimating Equation models were used to evaluate muscle variables, with "group" and "time" as factors. The model fit was adjusted, with 'torque' as a covariate.
Regarding muscle architecture, FL was greater in the severe COVID-19 group during early post-infection assessments for the RF at rest (p = 0.043). Additionally, both COVID-19 groups exhibited longer VL fascicles compared to controls (p = 0.032). TAC displacement was reduced in the severe COVID-19 group (RF: p = 0.008; VL: p = 0.047) compared to control. TAC stiffness did not differ between groups (p = 0.517), but torque production demonstrated an effect on this variable (p = 0.001). Both COVID-19 groups presented reduced PA for the VL at rest (p = 0.012) compared to control. Additionally, torque played a crucial role in influencing PA in both muscles, at rest and during contraction.
Participants with severe COVID-19 exhibited alterations in muscle architecture, which may contribute to persistent muscular weakness even one-year post-infection. The findings underscore the potential role of muscle strength, particularly the impact of torque on TAC stiffness and PA across all groups. Long COVID-19 rehabilitation and exercise physiologists should prioritize quadriceps strengthening strategies to restore muscle architecture and optimize force transmission.
关于新冠病毒病（COVID-19）对骨骼肌形态和结构的长期影响的研究有限。因此，本研究旨在通过评估既往COVID-19感染在一年时间内对股四头肌结构和肌腱-腱膜复合体（TAC）特性的影响来填补这一空白，比较三个队列：中度COVID-19患者、重度COVID-19患者和健康对照组。
70名参与者纳入本研究并分为三组：中度COVID-19组（n = 22）、重度COVID-19组（n = 18）和对照组（n = 30）。对COVID组在1年内进行了四项评估。在等长测力计上进行最大自主等长（MVIC）膝关节伸展收缩，同时对股外侧肌（VL）和股直肌（RF）进行超声成像。在静息状态和MVIC期间获取肌纤维长度（FL）和羽状角（PA），以及TAC位移。使用广义估计方程模型评估肌肉变量，以“组”和“时间”作为因素。以“扭矩”作为协变量对模型拟合进行调整。
关于肌肉结构，在感染后早期评估中，重度COVID-19组静息时RF的FL更大（p = 0.043）。此外，与对照组相比，两个COVID-19组的VL肌纤维均更长（p = 0.032）。与对照组相比，重度COVID-19组的TAC位移减少（RF：p = 0.008；VL：p = 0.047）。各组之间TAC刚度无差异（p = 0.517），但扭矩产生对该变量有影响（p = 0.001）。与对照组相比，两个COVID-19组静息时VL的PA均降低（p = 0.012）。此外，在静息和收缩期间，扭矩在影响两块肌肉的PA方面都起着关键作用。
重度COVID-19患者表现出肌肉结构改变，这可能导致即使在感染后一年仍持续存在肌肉无力。研究结果强调了肌肉力量的潜在作用，特别是扭矩对所有组TAC刚度和PA的影响。长期COVID-19康复和运动生理学家应优先考虑股四头肌强化策略，以恢复肌肉结构并优化力的传递。
