Post-COVID-19 patients may have several sequelae, such as neuromuscular electrophysiological disorders (NED), which can be evaluated using the stimulus electrodiagnosis test (SET). However, no information is available about the reliability and agreement of SET-in diagnosing NED in COVID-19 patients.

Our aim was to verify the intra- and inter-rater reliability and agreement of SET measurements in the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), tibialis anterior (TA), and gastrocnemius lateralis (GL) of post-COVID-19 participants who experienced moderate or severe infection.

This is an observational prospective study that evaluated 20 post-COVID-19 patients (10 males and 10 females), age: 44.95±11.07 years, weight: 87.99±19.08kg, height: 1.69±0.09m. Two independent raters took two evaluations using the SET on RF, VM, VL, TA and GL of the right lower limb in each participant. The intra-class correlation coefficient (ICC) and 95% limits of agreement defined the quality and magnitude of the measures.

For intra-rater reliability, all measurements presented correlations classified as high or very high (ICC: 0.71-1.0). For the inter-rater reliability, rheobase, chronaxie, accommodation, and accommodation index presented high or very high correlations, except for the accommodation index of the GL (ICC=0.65), which was moderate.

The reliability of the SET obtained by independent raters was very high, except for the GL accommodation, which presented moderate ICC. Therefore, SET is a reliable tool for evaluating neuromuscular electrophysiological disorders in post-COVID-19 patients.

The SET test can be a reliable tool to assess NED in post-COVID-19 patients. Our results may improve understanding of peripheral NED assessment and thus guide treatment programs for post-COVID-19 patients.