Schaefer Laura V, Bittmann Frank N
Health Education in Sports, Department of Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany.
Regulative Physiology and Prevention, Department of Sports and Health Sciences, University of Potsdam, 14476 Potsdam, Germany.
Diagnostics (Basel). 2023 Feb 25;13(5):882. doi: 10.3390/diagnostics13050882.
Long COVID patients show symptoms, such as fatigue, muscle weakness and pain. Adequate diagnostics are still lacking. Investigating muscle function might be a beneficial approach. The holding capacity (maximal isometric Adaptive Force; AFiso) was previously suggested to be especially sensitive for impairments. This longitudinal, non-clinical study aimed to investigate the AF in long COVID patients and their recovery process. AF parameters of elbow and hip flexors were assessed in 17 patients at three time points (pre: long COVID state, post: immediately after first treatment, end: recovery) by an objectified manual muscle test. The tester applied an increasing force on the limb of the patient, who had to resist isometrically for as long as possible. The intensity of 13 common symptoms were queried. At pre, patients started to lengthen their muscles at ~50% of the maximal AF (AF), which was then reached during eccentric motion, indicating unstable adaptation. At post and end, AFiso increased significantly to ~99% and 100% of AF, respectively, reflecting stable adaptation. AF was statistically similar for all three time points. Symptom intensity decreased significantly from pre to end. The findings revealed a substantially impaired maximal holding capacity in long COVID patients, which returned to normal function with substantial health improvement. AFiso might be a suitable sensitive functional parameter to assess long COVID patients and to support therapy process.
新冠长期症状患者表现出疲劳、肌肉无力和疼痛等症状。目前仍缺乏充分的诊断方法。研究肌肉功能可能是一种有益的方法。先前有人提出，保持能力（最大等长适应性力量；AFiso）对损伤特别敏感。这项纵向非临床研究旨在调查新冠长期症状患者的AF及其恢复过程。通过客观化的徒手肌力测试，在三个时间点（前：新冠长期症状状态，后：首次治疗后立即，结束：恢复）对17名患者的肘部和髋部屈肌的AF参数进行了评估。测试者在患者肢体上施加逐渐增加的力，患者必须尽可能长时间地进行等长抵抗。询问了13种常见症状的强度。在前阶段，患者在最大AF（AF）的约50%时开始拉长肌肉，然后在离心运动期间达到最大AF，这表明适应性不稳定。在后阶段和结束时，AFiso分别显著增加到AF的约99%和100%，反映出适应性稳定。三个时间点的AF在统计学上相似。症状强度从前期到结束时显著降低。研究结果显示，新冠长期症状患者的最大保持能力严重受损，随着健康状况的显著改善，其恢复到正常功能。AFiso可能是评估新冠长期症状患者并支持治疗过程的合适敏感功能参数。
