Publications
Normative myotonometric values of pelvic floor and lumbar paraspinal muscles in women
Authors: Daiana Priscila Rodrigues-de-Souza 1, 2, Sandra Alcaraz-Clariana 1, Lourdes Garcia-Luque 1, Maria Cristina Carmona-Perez 1, Amaranta De Miguel-Rubio 1, Francisco Alburquerque-Sendin 1, 2
Affiliations:
- Department of Nursing, Pharmacology and Physical Therapy, Faculty of Medicine and Nursing, University of Cordoba, 14004 Cordoba, Spain
- Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Cordoba, Spain
Journal: Nature - Scientific Reports - September 2026, In Press (DOI: 10.1038/s41598-026-68669-2)
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Field & Applications:
- Medical
- Normatives
- Women's health
- Muscle symmetry
- Gerontology / Ageing
- Methodology
Muscle mechanical properties (MMPs) of pelvic floor (PFM) and lumbar paraspinal muscles (LPM) are used to characterize musculoskeletal behavior in women. However, side‑specific normative data and their associations with female‑specific factors remain limited. This study aimed to establish side‑specific normative values, and examine the effects of age, body mass index (BMI), vaginal delivery, menopausal status and physical activity.
The MMPs (frequency, stiffness, logarithmic decrement, relaxation and creep) of 116 healthy women (18–65 years) were obtained for PFM and LPM on the right and left sides using a handheld myotonometric device.
Overall, bilateral symmetry was observed for most MMPs, although small asymmetries emerged mainly in PFM viscoelastic parameters within specific subgroups. Age and BMI showed negligible relations with PFM (Spearman’s correlation (rs) < 0.20), whereas age was positively associated with frequency (rs = 0.25–0.40), stiffness (rs = 0.45–0.53) and decrement (rs = 0.59–0.60), and negatively associated with relaxation in LPM. Vaginal delivery was associated with modest changes in PFM viscoelastic properties (creep: 0.28 < rank-biserial correlation (rrb) < 0.32) and greater increases in LPM tone and stiffness (0.30 < rrb < 0.51). Menopausal status was associated with increased stiffness (> 150 N/m) and reduced viscoelasticity at LPM level. Physical activity showed minimal associations.
These findings indicate region‑dependent lumbopelvic muscle behavior shaped by female‑specific biological factors, supporting bilateral and region‑specific assessment when using myotonometry.
Keywords: biomechanical properties, healthy women, lumbopelvic region, reference values, tonometry
This study provides side‑specific normative values for PFM and LPM mechanical properties in healthy women and shows that bilateral symmetry at rest could be related to specific biological and lifestyle factors. Mechanical behavior shows region-specific associations, with age and menopausal status being primarily associated with increased stiffness and reduced viscoelastic properties at the LPM level, while history of vaginal delivery is related to PFM and LPM mechanical properties in opposite manner. These findings highlight the importance of region‑specific interpretation and explicit bilateral assessment when applying myotonometry in both research and clinical contexts.