Repeatability and reproducibility of the pressure biofeedback unit

Introduction: Although the pressure biofeedback unit (PBU) is used for muscular assessment and training, there is little evidence of its reproducibility and repeatability.Objective: This study aims to assess intra-and inter-rater reproducibility and repeatability of the PBU in the assessment of the transverse abdominal (TrA), internal oblique (IO), low back multifidi, and deep neck flexors (DNF).Methods: Fifty individuals had three muscular groups tested: TrA/IO, lower back multifidi, and DNF. For repeatability, one rater did three consecutive measures; for intra-rater reproducibility the same rater did two measures with seven-day intervals, and for inter-rater reproducibility, three raters, on the same day, did the measures. Data were analyzed with: Intraclass Correlation Coefficient (ICC), Standard Error of Measurement (SEM), and Minimal Detectable Change (MDC). (alpha = 0,05).Results: Repeatability: TrA/IO (ICC = 0.847), Multifidi (ICC = 0.860), DNF (ICC = 0.831). Inter-rater reproducibility: TrA/IO (ICC = 0.876), Multifidi (ICC = 0.508), DNF (ICC = 0.442). Intra-rater reproducibility: TrA/IO (ICC = 0.747), Multifidi (ICC = 0.293), DNF (ICC = 0.685). Except for Multifidi, all the SEM values were less than 10 mmHg and the MDC values were less than 15 mmHg.Conclusions: The PBU can be used with reliability by different evaluators, although the evaluation of multifidi is not indicated. (C) 2021 Elsevier Ltd. All rights reserved.