Effects of a plank-based strength training programme on muscle activation in patients with long COVID: a case series

Abstract

Background. This study aimed to analyse the effects of a plank-based strength training programme on muscle activation in patients with long COVID. Subjects and methods. Case series study that included patients with long COVID who participated in a 12-week trunk and pelvic muscle strength training programme. Clinical variables and the modified fatigue impact scale (MFIS) were used to assess fatigue levels. Percentage of muscle activation during a core muscle plank was measured via surface electromyography. Pre-and post-intervention results were compared using the Wilcoxon signed-rank test and evaluated with Cohen’s D effect size (ES). Results. Twenty-one subjects participated in the study; 81% female, mean age 47.5 years (range: 28-55 years), and median duration of symptoms 21 months (range: 5-24 months); 90.5% of the participants experienced fatigue (MFIS score ≥ 38). Muscle activation during plank exercises improved across all muscles after the intervention, with significant increases in the left (p = 0.011, medium ES) and right external oblique (p =0.039, small ES) muscles and the right latissimus dorsi muscle (p = 0.039, small ES). Additionally, significant reductions in fatigue were observed in the total MFIS score (p = 0.004, medium ES) and in the physical (p < 0.001, large ES) and psychosocial subscales (p = 0.033, small ES). Conclusions. Results suggest that a plank-based strength training programme may be effective in enhancing trunk and pelvic muscle activation in individuals with long COVID.