Knowledge regarding the elastometric properties of the superficial pelvic floor muscles (sPFMs) in clinical populations is limited. Specifically, there is a lack of comparative studies investigating sPFM stiffness in healthy women versus those suffering from chronic pelvic pain conditions such as pudendal neuralgia (PN). The aim was to compare superficial pelvic floor stiffness using shear-wave elastography (SWE) between healthy women and those with PN.

An observational case–control study was conducted in accordance with STROBE guidelines, including adult women (≥18 years) with gynaecologist-diagnosed PN (symptoms ≥3 months) and healthy controls without chronic pelvic pain or pelvic floor dysfunction. PN inclusion criteria were pain in the pudendal nerve territory, worsened by sitting, not waking the patient at night, no objective sensory loss, and a positive response to a diagnostic pudendal nerve block [1]. Exclusion criteria included major psychiatric, neurological (except PN), internal, orthopaedic, or oncological disease, botulinum toxin treatment or pelvic surgery within 12 months, incomplete questionnaires, or refusal/withdrawal of consent.
	Imaging was performed using the ultrasound system equipped with SWE software. Tissue stiffness was quantified in kilopascals (kPa), with the display scale set from 0 to 800 kPa. To ensure measurement validity, real-time quality indicator were used: the Reliability Index (RLB), with values > 90% considered valid. 
	Measurements were performed by placing a 2 mm diameter circular Region of Interest (ROI) in a uniformly green area on the RLB map. Shell analysis was employed to identify and compare two specific locations within each muscle: the site of maximum stiffness (b-site) and the site of minimum stiffness (a-site).
	Muscle visualisation was performed as follows: m. bulbospongiosus, m. ischiocavernosus, and m. transversus perinei superficialis were examined with the transducer placed in the transverse plane and tilted toward the anal opening on both the left and right sides of the perineum, in accordance with protocol [2]. 
     Using a two-sided independent-groups design (α = 0.05, power = 80%, allocation ratio 1:1), and assuming a conservative medium effect size (Cohen’s d ≈ 0.6), the required sample size was 42 women per group; therefore, 45–50 women per group should be recruited to account for incomplete data.
     Statistical analyses were performed using IBM SPSS Statistics, version 30.0. Continuous variables are presented as medians and interquartile ranges (IQRs). Differences were evaluated using the Mann–Whitney U test, with a significance level of p < 0.05.

The observational case–control study included 44 women with PN and 44 healthy controls. Age was similar, and BMI did not differ significantly. Women with PN demonstrated significantly greater muscle stiffness than healthy controls (p < 0.001). The most dramatic differences were observed at sites of highest stiffness (b-sites) in the right m. bulbospongiosus (median 612.0 kPa, IQR 423.0–695.5 in PN vs median 26.5 kPa, IQR 23.0–167.2 in controls; p < 0.001) and left m. bulbospongiosus (median 572.0 kPa, IQR 408.5–665.5 in PN vs median 149.0 kPa, IQR 39.5–330.0 in controls; p < 0.001). Significant elevations were also confirmed for the m. ischiocavernosus and transverse perineal muscles (p < 0.001) (Table 1).

PN is characterised by a marked increase in sPFM stiffness compared with healthy women. These findings suggest that sPFM hypertonicity is a core pathological feature of PN. Significant relationships between m.bulbospongiosus stiffness and sexual, vaginal, and urinary dysfunction indicate that SWE provides a robust, non-invasive objective marker for assessing myofascial changes, potentially guiding targeted physiotherapeutic interventions.

Women with PN had significantly higher sPFM stiffness on SWE than healthy controls, with the greatest differences in the m. bulbospongiosus. These findings confirm the study aim and indicate that superficial pelvic floor hyperstiffness is a distinguishing feature of PN.

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