Instruments and Parameters for Evaluating Upper Limb Motor Fatigability in Individuals with Neuromuscular Diseases: Systematic Review

Background. Neuromuscular diseases present a set of clinical and pathological disabilities that include muscle weakness and atrophy, perception of fatigue, fatigability, and contracture. Motor fatigability compromises the ability of the individual to generate muscle strength and perform their daily activities. Quantitative measures of strength and motor fatigability are important to determine the clinical progression of the disease and the response to the proposed treatments. Thus, the aim of this study was to identify the equipment and protocols frequently used to assess upper limb motor fatigability in patients with neuromuscular disease. Methods. Information such as equipment used to induce motor fatigability, body segment or joint studied, movement analyzed, type of contraction, and protocol utilized for the test was analyzed. Joanna Briggs Scale and Newcastle-Ottawa Scale assessed the methodological quality of the studies. In addition, a checklist was prepared by the research group to assess the protocols presented in the referred studies. Results. The isokinetic and handgrip dynamometers were the most utilized equipment to induce motor fatigability. 83% of the studies had a design with low methodological rigor and half of them with high risk of bias. In the analysis of the protocols utilized to induce motor fatigability, one study was classified as regular and the other ones as good. Conclusion. The methodological topics to assess motor fatigability were incompletely described considering the electrophysiological and biomechanical approach. Although the motor fatigability in the upper limb was evaluated using isokinetic and handgrip equipment, the absence of a gold standard protocol still compromises the understanding of clinical progression and responses to the treatments in the neuromuscular diseases. This trial is registered with CRD42021206934.