Correlation between biomechanical parameters, pelvic morphometry, and risk factors for urinary incontinence in older women: a dynamic magnetic resonance imaging study
DOI:
https://doi.org/10.17267/2238-2704rpf.2026.e6679Keywords:
Urinary Incontinence, Pelvic Floor Disorders, Pelvis, Lumbosacral Region, Aged, Women, Magnetic Resonance ImagingAbstract
INTRODUCTION: Urinary continence depends on the interaction between muscular, ligamentous, and biomechanical structures that support the bladder and urethra. Morphometric and postural parameters, such as lumbosacral and pelvic angles, pelvic floor-to-bladder distances, and anatomical diameters, help to understand this support, while outcomes like bladder displacement and pelvic floor muscle contractile response reflect its functionality. Failures in this interaction constitute predisposing factors for urinary incontinence (UI) in older women. OBJECTIVE: To analyze the correlation between pelvic and lumbosacral morphometric measures and predisposing factors for urinary incontinence in older women. METHODS: This cross-sectional observational study included 22 women over 60 years of age (mean 71.5 years). The participants were assessed using dynamic magnetic resonance imaging to measure pelvic and lumbosacral angles and distances, and by surface electromyography to evaluate the contractile response of the pelvic floor muscles. Associations were analyzed using Pearson’s and Spearman’s correlation coefficients, adopting a 5% significance level. RESULTS: Correlation analyses revealed a positive association between body mass index and pubococcygeal distance (r = 0.463). Conversely, negative correlations were observed between age and pelvic inclination angle (PIA) (r = -0.476), between PIA and UI (r = -0.448), between the anteroposterior diameter (APD) and the presence of UI (r = -0.543), between the lumbosacral angle (LSA) and PIA (r = -0.433), and between maximum non-sustained contraction (NSC) and the pelvic floor-to-bladder distance during straining (PFBD-S) (r = -0.485). CONCLUSION: In older women, morphometric measures of the pelvis and lumbosacral region show significant associations with predisposing factors for urinary incontinence. The interaction between structural support and pelvic floor muscle functionality appears to be a key determinant of urinary continence, highlighting the importance of comprehensive physiotherapeutic assessments that consider both morphometric parameters and contractile muscle response.
Downloads
References
1. Grewar H, McLean L. The integrated continence system: a manual therapy approach to the treatment of stress urinary incontinence. Man Ther. 2008;13(5):375–86. https://doi.org/10.1016/j.math.2008.01.003
2. Kiapour A, Joukar A, Elgafy H, Erbulut DU, Agarwal AK, Goel VK. Biomechanics of the sacroiliac joint: anatomy, function, biomechanics, sexual dimorphism, and causes of pain. Int J Spine Surg. 2020;14(Suppl1):3-13. https://doi.org/10.14444/6077
3. Imai N, Suzuki H, Sakagami A, Hirano Y, Endo N. Correlation of the anatomical sacral slope with pelvic incidence in female patients with developmental hip dysplasia: a retrospective cross-sectional study. J Orthop Surg Res. 2020;15:486. https://doi.org/10.1186/s13018-020-02022-9
4. Brandão S, Parente M, Mascarenhas T, Silva ARG, Ramos I, Jorge RN. Biomechanical study on the bladder neck and urethral positions: simulation of impairment of the pelvic ligaments. J Biomech. 2015;48(2):217-23. https://doi.org/10.1016/j.jbiomech.2014.11.045
5. Moreira SFS, Girão MJBC, Sartori MGF, Baracat EC, Lima GR. Bladder Neck Mobility and Functional Pelvic Floor Evaluation in Women with and without Stress Urinary Incontinence, According to Hormonal Status. Rev Bras Ginecol Obstet. 2002;24(6):365-70. https://doi.org/10.1590/S0100-72032002000600002
6. DeLancey JOL. Structural support of the urethra as it relates to stress urinary incontinence: the hammock hypothesis. Am J Obstet Gynecol. 1994;170(6):1713-23. https://doi.org/10.1016/s0002-9378(94)70346-9
7. Ashton-Miller JA, DeLancey JOL. Functional Anatomy of the Female Pelvic Floor. Annals of the New York Academy of Sciences. 2007;1101:266-96. https://doi.org/10.1196/annals.1389.034
8. Bø K, Hilde G, Tennfjord MK, Sperstad JB, Engh ME. Pelvic floor muscle function, pelvic floor dysfunction and diastasis recti abdominis: Prospective cohort study. Neurourol Urodyn. 2017;36(3):716-21. https://doi.org/10.1002/nau.23005
9. Fielding JR. Practical MR imaging of female pelvic floor weakness. Radiographics. 2002;22(2):295-304. https://doi.org/10.1148/radiographics.22.2.g02mr25295
10. Pihl S, Uustal E, Blomberg M. Anovaginal distance and obstetric anal sphincter injury: a prospective observational study. Int Urogynecol J. 2019;30(6):939-44. https://doi.org/10.1007/s00192-018-3838-5
11. Megadhana IW, Marta KF, Arijaya DNK. Wide Genital Hiatus (GH) and Short Perineal Body (PB) as Risk Factors for Stage III-IV Uterine Prolapse. Eur J Med Health Sci. 2025;7(2):23-6. https://doi.org/10.24018/ejmed.2025.7.2.2257
12. Dancey CP, Reidy J. Statistics without maths for psychology. 7th ed. Harlow: Pearson; 2017.
13. Subak LL, Richter HE, Hunskaar S. Obesity and urinary incontinence: epidemiology and clinical research implication. J. Urol. 2009;182(6 Suppl):S2-7. https://doi.org/10.1016/j.juro.2009.08.071
14. Whitcomb EL, Subak LL. Effect of weight loss on urinary incontinence in women. Res Rep Urol. 2011;3:123-32. https://doi.org/10.2147/oaju.s21091
15. Dietz HP. Pelvic floor ultrasound: a review. Clin Obstet Gynecol. 2017;60(1):58-81. https://doi.org/10.1097/grf.0000000000000264
16. Swenson CW, Masteling M, DeLancey JO, Nandikanti L, Schmidt P, Chen L. Aging effects on pelvic floor support: a pilot study comparing young versus older nulliparous women. Int Urogynecol J. 2020;31(3):535-43. https://doi.org/10.1007/s00192-019-04063-z
17. Lemos AQ, Brasil CA, Alvares CM, Passos JCG, Lordêlo PP, Sá KN. The relation of the pelvis and the perineal function in incontinent women: a neglected subject. Neurourol Urodyn. 2018;37(8):2799-2809. https://doi.org/10.1002/nau.23772
18. Muellner M, Haffer H, Moser M, Chiapparelli E, Dodo Y, Amini DA, et al. Paraspinal musculature impairment is associated with spinopelvic and spinal malalignment in patients undergoing lumbar fusion surgery. Spine J. 2022;22(12):2006-16. https://doi.org/10.1016/j.spinee.2022.07.103
19. Hoyte L, Damaser M. Biomechanics of the female pelvic floor. 1st ed. London: Academic Press; 2016.
20. Reis AM, Brito LGO, Teixeira CPF, Araújo CC, Facio FA, Herrmann V, et al. Is There a Difference in Whole Body Standing Posture in Women With Urinary Incontinence Based on the Presence of Myofascial Dysfunction in the Pelvic Floor Muscles? Phys Ther. 2021;101(10):pzab171. https://doi.org/10.1093/ptj/pzab171
21. Capson AC, Nashed J, McLean L. The role of lumbopelvic posture in pelvic floor muscle activation in continent women. J Electromyogr Kinesiol. 2011;21(1):166-77. https://doi.org/10.1016/j.jelekin.2010.07.017
22. d'Aulignac D, Martins JAC, Pires EB, Mascarenhas T, Jorge RMN. A shell finite element model of the pelvic floor muscles. Comput Methods Biomech Biomed Engin. 2005;8(5):339-47. https://doi.org/10.1080/10255840500405378
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Mariana Santos de Lucca, Rubia Motta da Silva, Maycon Sousa Pegorari, Karla Helena Vilaça e Silva, Eduardo Ferriolli, Lislei Patrizzi
This work is licensed under a Creative Commons Attribution 4.0 International License.
This work is licensed under a Creative Commons Attribution 4.0 International License.
