December 2021

Absolute and Relative Reliability of the Assessment of the Muscle Mechanical Properties of Pelvic Floor Muscles in Women with and without Urinary Incontinence

Authors: Daiana Priscila Rodrigues-de-Souza 1, Sandra Alcaraz-Clariana 1, Lourdes Garcia-Luque 1, Cristina Carmona-Perez 1, Juan Luis Garrido-Castro 2, 3, Ines Cruz-Medel 1, Paula R. Camargo 4, Francisco Alburquerque-Sendin 1, 3


  1. Department of Nursing, Pharmacology and Physical Therapy, Faculty of Medicine and Nursing, University of Cordoba, 14004 Cordoba, Spain
  2. Department of Computer Science and Numerical Analysis, Rabanales Campus, University of Cordoba, 14071 Cordoba, Spain
  3. Maimonides Biomedical Research Institute of Cordoba (IMIBIC), 14004 Cordoba, Spain
  4. Laboratory of Analysis and Intervention of the Shoulder Complex, Department of Physical Therapy, Universidade Federal de Sao Carlos, Rodovia Washington Luis km 235, Sao Carlos 13565-905, SP, Brazil

Journal: Diagnostics - December 2021, Volume 11, Issue 12, Article no. 2315 (DOI: 10.3390/diagnostics11122315)

An analysis of the muscle mechanical properties (MMPs) of the pelvic floor muscles (PFMs) is relevant for understanding the physiopathology of urinary incontinence (UI). However, there is no objective and reliable methodology currently available for quantifying the MMPs of PFMs. Thus, the objective was to determine the intra-rater and inter-rater reliability of the MMPs of PFM assessment with a hand-held tonometer device, called the MyotonPRO, in young women with and without UI.

Sociodemographic and pelvic floor questionnaires, plus MMPs of PFMs were assessed in 38 nulliparous women with UI and 40 matched healthy women by two trained physiotherapists on two different occasions, 48–72 h apart.

Good to excellent absolute reliability was found for tone, stiffness, and decrement of both intra- and inter-rater analyses in both study groups (Intraclass Correlation Coefficient ranged from 0.75 to 0.92), with a trend of lower values for relaxation and creep. The standard error of measurement (SEM) did not achieve 10% of the mean values for any MMPs. The minimum detectable change (MDC) values were also provided for clinical applications.

In conclusion, the relative reliability of tone, stiffness, and the assessment of the decrement of PFMs with MyotonPRO is good to excellent for UI and healthy women. The SEM and MDC values were acceptable for their application in clinical settings.


Keywords: muscle tone, tissue stiffness, pelvic floor disorders, young women

The relative reliability of the assessment of MMPs of the PFMs using a handheld tonometer is good to very good for intra-rater and inter-rater reliability in urinary incontinent and healthy women, which supports its use in women with and without UI. However, caution is recommended for relaxation and creep values, mainly for inter-rater evaluations. In addition, SEM and MDC values are acceptable for their application in clinical settings.