Morin, Mélanie, Salomoni, Sauro E., Stafford, Ryan E., Hall, Leanne M., and Hodges, Paul W. (2022) Validation of shear wave elastography as a noninvasive measure of pelvic floor muscle stiffness. Neurourology and Urodynamics, 41 (7). pp. 1620-1628.

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Abstract

Objectives :To investigate the validity of shear wave elastography (SWE) as a measure of stiffness of the puborectalis muscle by examining: (1) the relationship between puborectalis muscle stiffness and pelvic floor muscle (PFM) activation at different intensities; and (2) the relationship between puborectalis stiffness and pelvic floor morphometry during contractions at different intensities.

Methods: Fifteen healthy asymptomatic women performed 6-s isometric PFM contractions at different intensities (0, 10%, 20%, 30%, 50%, 75%, and 100% of maximal voluntary contraction) guided by intravaginal electromyography (EMG). Stiffness of the puborectalis muscle was measured using SWE by calculating the average shear modulus in regions of interest that contained puborectalis muscle fibers parallel to the transducer. Pelvic floor morphometry was assessed in the mid-sagittal plane using transperineal B-mode ultrasound imaging. Shear modulus, EMG (root mean square amplitude) and pelvic floor morphometry parameters were normalized to the value recorded during maximal voluntary contraction. To assess the relationship between stiffness and pelvic floor activation/morphometry, coefficient of determination (r2) was calculated for each participant and a group average was computed.

Results: Shear modulus and EMG were highly correlated (average r2; left 0.90 ± 0.08, right 0.87 ± 0.15). Shear modulus also strongly correlated with bladder neck position (x-axis horizontal coordinates relative to the pubic symphysis), anorectal rectal angle and position, levator plate angle, and antero-posterior diameter of the levator hiatus (average r2: range 0.62–0.78).

Conclusions: These findings support the validity of SWE to assess puborectalis muscle stiffness in females. Stiffness measures were strongly associated with PFM EMG and pelvic floor morphometry and may be used to indirectly assess the level of activation of the puborectalis muscle without the use of more invasive techniques. By overcoming limitations of current assessment tools, this promising noninvasive and real-time technique could enable important breakthrough in the pathophysiology and management of pelvic floor disorders.

Item ID:	79185
Item Type:	Article (Research - C1)
ISSN:	1520-6777
Copyright Information:	© 2022 Wiley Periodicals LLC.
Funders:	National Health and Medical Research Council of Australia (NHMRC)
Projects and Grants:	NHMRC APP110290, NHMRC APP1091302
Date Deposited:	05 Jul 2023 01:13
FoR Codes:	42 HEALTH SCIENCES > 4201 Allied health and rehabilitation science > 420106 Physiotherapy @ 50% 42 HEALTH SCIENCES > 4201 Allied health and rehabilitation science > 420109 Rehabilitation @ 50%
SEO Codes:	20 HEALTH > 2001 Clinical health > 200105 Treatment of human diseases and conditions @ 25% 28 EXPANDING KNOWLEDGE > 2801 Expanding knowledge > 280112 Expanding knowledge in the health sciences @ 75%
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