Muscular dystrophies (DMs) represent a complex, varied, and important subset of neuromuscular disorders, caused by genetic alterations that result in skeletal muscle degeneration and progressive muscle weakness, generating changes in motor function and directly impacting functionality. Fatigue is a common symptom that prevents adequate muscle contraction and interferes with daily activities, reducing the quality of life.

To assess motor function, muscle strength, and fatigue in individuals with DM.

Quantitative and cross-sectional study, carried out in a state rehabilitation center in Goiânia, Goiás, Brazil. and data collection took place between March and July 2022. The research consisted of individuals with a confirmed diagnosis of muscular dystrophy, over 18 years and who attended the neuromuscular diseases clinic of the institution. Motor function was assessed using the Motor Function Measurement Scale (MFM-32), muscle strength using the Medical Research Council (MRC), and fatigue using the Fatigue Severity Scale (FSS). All evaluations were performed by the same, duly trained evaluator. The parametricity of the data was verified using a normalized Q-Q plot and a histogram of standardized residues. Comparison between groups was tested by applying the Analysis of Variance (ANOVA) and Pearson's Chi-square tests. The significance level adopted was p < 0.05.

The sample consisted of 66 participants, with a mean age of 35.7(±13) years, most of them male 39(59.1%). The sample was divided into three groups according to the presented diagnosis. The group with limb girdle muscular dystrophy (LGMD) was composed of 30(45.5%) individuals, Duchenne Muscular Dystrophy (DMD) 17(25.8%), and Myotonic Dystrophy type 1 (DM1) with 19(28.8%). %). The mean found in the MFM-32 score was 54.9 ± 29.5, with the DMD having the lowest value of 23.5±12.6 with a statistical difference between groups (p<0.001). The MRC presented a total average of 32.4±17.4 with the DMD presenting lower values of 12.8±5.8 with the statistical difference (p<0.001). The general FSS presented a mean of 36.0±13.3, predominantly classified as moderate in DM1 11(57.9), without fatigue in LGMD 11(36.7) and DMD and 6(35.3) with no difference between the groups.

Motor function and muscle strength were reduced in individuals with DM, and DMD showed lower values concerning LGMD and DM1, showing greater severity of the disease. Fatigue was not reported in most individuals with LGMD and DMD, however, it was moderate in DM1. Implications: This article is innovative in describing the clinical aspects of a rare disease, and the sample size of this study proved to be satisfactory, allowing a more robust and detailed interpretation of the functionality of this population, and enabling better rehabilitation strategies.