Ultrasound Elastography in Benign Gynecology: A Scoping Review.

OBJECTIVE: To perform a scoping review of the literature in which ultrasound elastography (UE) has been used in benign gynecology and identify avenues for its use in future research and clinical implementations. METHODS: A structured search of EMBASE, Medline and Cochrane databases was conducted (last search date April 15th, 2022). Eligible studies included adult participants with female pelvic anatomy. English language papers focusing on the utility of ultrasound elastography applied to benign gynecology were included. Narrative reviews, conference abstracts, and letters to the editor were excluded. Two independent reviewers screened titles and abstracts for inclusion, a third reviewer was consulted in cases of disagreement. Study quality was assessed by a checklist for study implementation and elastography technique. Extracted data included elastography technology, gynecologic application, opportunities for clinical implementation, and strengths and limitations. RESULTS: The search returned 2026 studies. A total of 40 studies, published between 2013 and 2022, were retained for data extraction. Studies most frequently used shear wave elastography as the method of UE (n = 23), followed by strain elastography (n = 13) and acoustic radiation force impulse (n = 4). Most common clinical applications for UE were the diagnosis of adenomyosis and uterine fibroids (27.5%), assessment of pelvic floor muscle function (22.5%), and describing the elastic properties of polycystic ovaries (17.5%) and the uterine cervix (15.0%). Limitations of the technology were identified as the lack of published reference values for gynecologic organs and difficulties in assessing tissues deep to the transducer. CONCLUSION: Future research is needed to validate the use of ultrasound elastography in gynecology under both normal and pathologic conditions.

The acute effects of running on pelvic floor morphology and function in runners with and without running-induced stress urinary incontinence.

INTRODUCTION AND HYPOTHESIS: The aim of this study was to examine the impact of a single running session on pelvic floor morphology and function in female runners, and to compare those with and without running-induced stress urinary incontinence (RI-SUI). METHODS: This cross-sectional, observational study involved two groups: female runners who regularly experienced RI-SUI (n = 19) and runners who did not (n = 20). Pelvic floor muscle (PFM) properties were assessed using intravaginal dynamometry during maximal voluntary contractions (MVC) and during passive tissue elongation. The morphology of the pelvic floor was assessed at rest, during MVC and during maximal Valsalva maneuver (MVM) using 2D and 3D transperineal ultrasound imaging before and after a running protocol. Mixed-effects ANOVA models were used to compare all outcomes between groups and within-groups, including the interaction between group and time. Effect sizes were calculated. RESULTS: No changes in PFM function assessed using intravaginal dynamometry were observed in either group after the run. Significant and large within-group differences were observed on ultrasound imaging. Specifically, the area and antero-posterior diameter of the levator hiatus were larger after the run, the bladder neck height was lower after the run, and the levator plate length was longer after the run (p ≤ 0.05). At the peak MVM and MVC, the bladder neck height was lower after the run than before the run (p ≤ 0.05). No between-group differences were observed for any outcomes. CONCLUSIONS: Running appears to cause transient strain of the passive tissues of the female pelvic floor in runners both with and without RI-SUI, whereas no concurrent changes are observed in PFM contractile function.

Management of urinary incontinence in females by primary care providers: a systematic review.

OBJECTIVE: To describe primary care provider (PCP) practices for the assessment and management of females with urinary incontinence (UI), and appraise these practices relative to recommendations made in high-quality clinical guidelines. METHODS: Studies were searched in four databases (MEDLINE, EMBASE, CINAHL, Web of Science) from their respective inception dates to 6 March 2023. All studies describing UI evaluation and management practices used by PCPs for female patients were eligible. Two reviewers independently selected studies assessed their quality and extracted data. A narrative synthesis of included studies was performed to describe practices. Relevant evaluation and management practices were then compared to recommendations that were consistent across current high-quality UI guidelines. Pharmacotherapy, referrals, and follow-ups were reported descriptively only. RESULTS: A total of 3475 articles were retrieved and, among those, 31 were included in the review. The majority reported a poor-moderate adherence to performing a pelvic examination (reported adherence range: 23-76%; based on eight studies), abdominal examination (0-87%; three studies), pelvic floor muscle assessment (9-36%; two studies), and bladder diary (0-92%; nine studies), while there was high adherence to urine analysis (40-97%; nine studies). For the conservative management of UI, studies revealed a poor-moderate adherence to recommendations for pelvic floor muscle training (5-82%; nine studies), bladder training (2-53%; eight studies) and lifestyle interventions (1-71%; six studies). Regarding pharmacotherapy, PCPs predominantly prescribed antimuscarinics (2-46%; nine studies) and oestrogen (2-77%; seven studies). Lastly, PCPs referred those reporting UI to medical specialists (5-37%; 14 studies). Referrals were generally made <30 days after diagnosis with urologists being the most sought out professional to assess and treat UI. CONCLUSION: This review revealed poor-moderate adherence to clinical practice guideline recommendations. While these findings reflect high variability in reporting, the key message is that most aspects of patient care for female UI provided by PCPs needs to improve.

Differences in pelvic floor muscle morphology and function between female runners with and without running-induced stress urinary incontinence.

OBJECTIVE: To investigate the differences in pelvic floor muscle (PFM) morphology and function between female runners with and without running-induced stress urinary incontinence (RI-SUI). DESIGN: This was a cross-sectional, observational study. METHODS: Experienced female runners were recruited into two groups: runners who regularly experience RI-SUI (n = 19) and runners who do not (n = 20). Active and passive pelvic floor muscle (PFM) properties were assessed using intravaginal dynamometry during maximal voluntary contractions (MVC) and during passive tissue elongation. The morphology of the urethra and PFMs was assessed using 2D and 3D transperineal ultrasound imaging. Independent t tests or Mann-Whitney U were used as appropriate to test group differences on all study outcomes, and Cohen's d effect sizes were calculated. RESULTS: The rate of force development during the MVC was significantly higher in participants reporting RI-SUI (p ≤ 0.05) and conversely, significantly lower during passive elongation of the PFMs (p ≤ 0.05) compared to runners with no history of leakage. Concurrently, the extent of bladder neck elevation between rest and maximum voluntary activation was significantly higher among those with RI-SUI compared to those without. Although not significant, small to moderate effect sizes were observed for other outcomes-active force outcomes measured during MVC tended to be higher in runners with RI-SUI, while passive force outcomes measured during passive tissue elongation tended to be lower. The cross-sectional area of the urethral wall and the area of the levator hiatus tended to be larger in runners with RI-SUI compared to those without. CONCLUSION: Runners who experience RI-SUI demonstrate better PFM contractile function but lower passive support when compared to their continent counterparts.

Characteristics Associated with Pelvic Floor Disorders among Female Canadian Armed Forces Members.

OBJECTIVES: Urinary incontinence (UI) and pelvic organ prolapse (POP) are prevalent pelvic floor disorders (PFDs) among the female population. In the military environment, being a non-commissioned member (NCM), and physically demanding occupations are factors associated with higher PFD risk. This study seeks to characterize the profile of female Canadian Armed Forces (CAF) members reporting symptoms of UI and/or POP. METHODS: Present CAF members (18-65 years) responded to an online survey. Only current members were included in the analysis. Symptoms of UI and POP were collected. Multivariate logistic regressions analyzed the relationships between PFD symptoms and associated characteristics. RESULTS: 765 active members responded to female-specific questions. The prevalence of self-reported POP and UI symptoms were 14.5% and 57.0%, respectively, with 10.6% of respondents reporting both. Advanced age (adjusted odds ratio [aOR]: 1.062, CI 1.038-1.087), a body mass index (BMI) categorized as obese (aOR: 1.909, [1.183-3.081]), parity ≥1 (e.g., aOR for 1: 2.420, [1.352-4.334]) and NCMs (aOR: 1.662, [1.144-2.414]) were factors associated with urine leakage. Parity of ≥2 (aOR: 2.351, [1.370-4.037]) compared to nulliparous and having a perception of a physically demanding job (aOR: 1.933, [1.186-3.148]) were associated with experiencing POP symptoms. Parity of ≥2 increased the odds of reporting both PFD symptoms (aOR: 5.709, [2.650-12.297]). CONCLUSION: Parity was associated with greater odds of experiencing symptoms of UI and POP. Higher age, higher BMI, and being an NCM were associated with more symptoms of UI, and the perception of having a physically demanding role increased the likelihood of reporting POP symptoms.

One in four women with stress urinary incontinence who are taught "the knack" maneuver adopt this motor pattern while coughing: A prospective interventional cohort study.

QUESTIONS: Do women with stress urinary incontinence (SUI) who receive instruction to perform the knack maneuver as part of a 12-week pelvic floor muscle training (PFMT) program perform it during voluntary coughing without specific instruction to do so, and are subjective and objective outcomes better among those who do than among those who do not demonstrate the knack during voluntary coughing? DESIGN: Secondary analysis of a prospective interventional cohort. PARTICIPANTS: Women with SUI. INTERVENTION: 12-week PFMT intervention including instruction to perform the knack. OUTCOME MEASURES: Performance of the knack before a voluntary cough as confirmed through ultrasound imaging. SUI severity determined subjectively (International Consultation on Incontinence Modular Questionnaire-Female Lower Urinary Tract Symptoms [ICIQ-FLUTS] overall score, ICIQ-FLUTS UI subscale score, 3-day bladder diary) and objectively (30-min pad test). RESULTS: Outcome data were available from 69 participants. At baseline, no participants performed the knack when asked to cough. At follow-up, more participants performed the knack during a voluntary cough [18/69 (26%), 95% confidence interval [CI] 15%-35%] than at baseline. The extent of improvement in SUI symptoms was not different between participants who did and did not demonstrate the knack during a voluntary cough [FLUTS-UI subscale score (d = 0.31, 95% CI -0.78 to 2.77, n = 69), FLUTS overall score (d = 0.26, 95% CI -1.52-4.23, n = 69), 30-min pad test (d = 0.03, 95% CI -9.35 to 10.32, n = 69), 3-day bladder diary (d = 0.03, 95% CI -4.07 to 3.60, n = 51)]. CONCLUSION: Approximately one in four women appear to adopt the knack as a motor response to a cough command, however, adopting the knack was not independently associated with greater improvements in SUI.

Automatic Plane of Minimal Hiatal Dimensions Extraction From 3D Female Pelvic Floor Ultrasound.

There is an increasing interest in the applications of 3D ultrasound imaging of the pelvic floor to improve the diagnosis, treatment, and surgical planning of female pelvic floor dysfunction (PFD). Pelvic floor biometrics are obtained on an oblique image plane known as the plane of minimal hiatal dimensions (PMHD). Identifying this plane requires the detection of two anatomical landmarks, the pubic symphysis and anorectal angle. The manual detection of the anatomical landmarks and the PMHD in 3D pelvic ultrasound requires expert knowledge of the pelvic floor anatomy, and is challenging, time-consuming, and subject to human error. These challenges have hindered the adoption of such quantitative analysis in the clinic. This work presents an automatic approach to identify the anatomical landmarks and extract the PMHD from 3D pelvic ultrasound volumes. To demonstrate clinical utility and a complete automated clinical task, an automatic segmentation of the levator-ani muscle on the extracted PMHD images was also performed. Experiments using 73 test images of patients during a pelvic muscle resting state showed that this algorithm has the capability to accurately identify the PMHD with an average Dice of 0.89 and an average mean boundary distance of 2.25mm. Further evaluation of the PMHD detection algorithm using 35 images of patients performing pelvic muscle contraction resulted in an average Dice of 0.88 and an average mean boundary distance of 2.75mm. This work had the potential to pave the way towards the adoption of ultrasound in the clinic and development of personalized treatment for PFD.

The Impact of Hypopressive Abdominal Exercise on Linea Alba Morphology in Women Who Are Postpartum: A Short-Term Cross-Sectional Study.

OBJECTIVE: The purpose of this study was to determine the acute effect of an abdominal hypopressive exercise (AHE) on linea alba morphology among women who are primiparous and to compare this effect with that of other common abdominal exercise modalities. METHODS: A cross-sectional study of 46 women 3 months after first delivery was conducted. B-mode ultrasound imaging of the interrectus distance (IRD) and linea alba distortion was performed 2 cm below (I-point) and above (S-point) the umbilicus and at the mid-point between the umbilicus and xiphoid process (X-point). Images were recorded at rest and during an AHE performed in a supine position, a semi curl-up (SCU), an abdominal drawing-in maneuver (ADIM), and a SCU performed after an initial ADIM (ADIM+SCU). RESULTS: The SCU exercise narrowed the IRD at the X- and S-points. Compared with SCU, AHE and ADIM widened the IRD at the S- and X-points. No significant differences were found when comparing the IRD at rest, during AHE and during ADIM, but AHE tended to narrow I-point IRD more than ADIM but to widen S-point IRD more than ADIM+SCU. No participant showed linea alba distortion during the AHE or ADIM. When compared, SCU increased the occurrence of distortion with respect to AHE and ADIM. The isolated hypopressive posture did not change the IRD or linea alba distortion. CONCLUSION: Among women who were postpartum, AHE seemed to narrow IRD below the umbilicus compared with ADIM without either of these 2 modalities generating linea alba distortion, as SCU or ADIM+SCU does. Thus, although no significant differences were found when comparing the IRD at rest and during AHE, the AHE could improve the tensile response of the linea alba without increasing the IRD. IMPACT: This is believed to be the first study to describe linea alba changes during AHE in women who are postpartum. AHE and ADIM seem to show different effects on infraumbilical IRD. The lack of distortion suggests that linea alba may undergo tensile loading at all levels.

Pelvic floor tissue damping during running using an intra-vaginal accelerometry approach.

BACKGROUND: While cumulative loading of the pelvic floor during exercise appears to increase the risk of developing pelvic floor disorders, the pathophysiologic role of pelvic floor loading is poorly understood. The aim of this exploratory study was to present a method for evaluating vibrational frequency damping of the female pelvic floor and to investigate the potential utility of this approach in a preliminary evaluation. METHODS: Female participants were instrumented with an intravaginal accelerometer and a hip-mounted accelerometer, then ran on a treadmill at 7 km/h and 10 km/h both before and after a 30-min self-selected pace. Displacement of the pelvic floor relative to the bony pelvis was calculated using double integration of the accelerometer data. Vibrational damping coefficients were calculated using a wavelet-based approach to determine the effect of continence status, parity, running speed and time on vibrational damping. FINDINGS: Seventeen women (n = 10 reported regularly leaking urine while exercising, while n = 7 reported not leaking) completed the running protocol. No differences in vibrational damping were detected between continent and incontinent women when all frequency bands were evaluated together, however significant effects of parity, time, running speed and continence status were found within specific frequency bands. Parous women demonstrated less damping in the 25-40 Hz band compared to nulliparae, damping in the 13-16 Hz band was lower after the 30-min run, and incontinent women demonstrated lower damping in the 4.5-5.5 Hz band than continent women when running at 7 km/h. INTERPRETATION: Intra-vaginal vibrational damping may be useful in detecting biomechanical mechanisms associated with pelvic floor disorders experienced by females during exercise.

What improvements in levator ani motor function lead to improvement in stress urinary incontinence signs and symptoms in females?

INTRODUCTION AND HYPOTHESIS: The objectives were to determine whether levator ani muscle (LAM) motor function is associated with female stress urinary incontinence (SUI) severity, and whether changes in LAM motor function induced through pelvic floor muscle training (PFMT) are associated with improvements in SUI signs and symptoms. METHODS: Pelvic morphology and LAM function were evaluated using ultrasound imaging and manual palpation using the elements of the PERFECT Scheme (Power, Endurance, Repetitions, Fast contractions, Elevation, Co-contraction and Timing) before and after women with SUI underwent a 12-week PFMT intervention. SUI severity was determined subjectively (ICIQ-FLUTS-UI) and objectively (30-min pad test [30MPT]). RESULTS: At baseline (n = 97), less leakage on the 30MPT was weakly associated with higher bladder neck position (ρs = -0.209,p = 0.044), yet with lower LAM function based on the PERFECT Scheme (overall score: ρs = 0.206, p = 0.043; repeated maximum voluntary contractions (MVCs): ρs = 0.203, p = 0.046; power/motor control: ρs = 0.214, p = 0.035). Lower symptom severity (ICIQ-FLUTS-UI) was associated with observed perineal lift during coughing (U = 34.000; p = 0.042). All measures of SUI severity and LAM function were significantly improved after PFMT intervention. Greater improvements in bladder neck elevation during MVC (ρs = -0.261, p = 0.027) and greater reductions in levator plate length during MVC (ρs = 0.292, p = 0.016) were weakly associated with greater reductions in leakage (30MPT), the latter also being associated with more improvement symptoms (ICIQ-FLUTS-UI; ρs = 0.238, p = 0.041). Greater improvement in the ability to repeat MVCs (ρs = 0.303, p = 0.009) was weakly associated with smaller improvements in symptoms (ICIQ-FLUTS-UI). CONCLUSION: Improvements in bladder neck support and elevation show weak associations with improvement in SUI signs and symptoms. LAM function as measured by the PERFECT Scheme is not associated with SUI severity in women, and improvements in LAM function when measured by the PERFECT Scheme are not associated with improvements in SUI signs and symptoms.

Pelvic floor muscle training as an adjunct to a midurethral sling: a single-blind randomised controlled trial.

INTRODUCTION AND HYPOTHESIS: This single-blind, randomised controlled trial was aimed at determining whether peri-operative physiotherapist-supervised pelvic floor muscle (PFM) training was superior to standard care (handout) in terms of improvements in stress urinary incontinence (SUI) symptoms, cure rate, and/or post-operative filling or voiding symptoms among women undergoing surgical mid-urethral sling (MUS) insertion for SUI. METHODS: Women with SUI were recruited from surgical wait lists at four participating urogynecology clinics. Participants were assessed at baseline (V1) then randomised (1:1 allocation) to receive supervised PFM training or a handout. Immediately following the 12-week intervention period (V2) and at 12 weeks following surgery (V3) the groups were compared based on the Female Lower Urinary Tract Symptoms (FLUTS) questionnaire total score and urinary incontinence, filling, and voiding subscale scores as well as on a standardised 30-min pad test administered by a blinded assessor. Intention-to-treat analyses were performed. RESULTS: A total of 52 participants were randomised to physiotherapy and 51 to the control group between December 2012 and August 2016. The groups were not different on any outcomes at V1 and all were improved at V3 compared with V1 (p < 0.001). At V3 the physiotherapy group reported significantly fewer UI symptoms (FLUTS UI subscale score) than the control group; yet, there were no group differences in FLUTS overall score or the pad test (p > 0.05). Based on a FLUTS UI subscale score <4, the cure rate at V3 was higher in the intervention group (73%) than in the control group (47%); (2.36 < OR < 3.47, p = 0.012). There were no group differences in cure rate at V3 based on a pad test (p = 0.27). No group differences were found in the filling or voiding symptoms at V3 (p > 0.05). No adverse events were reported. CONCLUSION: Physiotherapist-supervised PFM training improves SUI cure rates associated with surgical MUS insertion when considering symptoms of SUI, but does not improve post-operative continence function as measured by a pad test, nor does it lead to fewer post-operative voiding or filling symptoms.

An in-home rehabilitation program for the treatment of urinary incontinence symptoms in endometrial cancer survivors: a single-case experimental design study.

INTRODUCTION AND HYPOTHESIS: There is a high prevalence of urinary incontinence among endometrial cancer survivors. They are also known to present with pelvic floor muscle alterations. Evidence on the effects of conservative interventions for the management of UI is scarce. This study aims at verifying the effects of an in-home rehabilitation program, including the use of a mobile technology, to reduce UI severity in endometrial cancer survivors. METHODS: This study used a single-case experimental design with replications. Primary outcome for UI severity was the pad test, and secondary outcomes were the ICIQ-UI SF questionnaire and 3-day bladder diary. Pelvic floor muscle function was assessed using 2D-transperineal ultrasound and intravaginal dynamometry. Adherence was documented using mobile technology and an exercise log. Visual and non-parametric analyses of longitudinal data were conducted. RESULTS: Results show a reduction in UI severity for 87.5% of participants, with a significant relative treatment effect of moderate size (RTE: 0.30). Significant small relative treatment effects were found for the quick contraction and endurance dynamometric tests. CONCLUSION: This study provides new evidence that endometrial cancer survivors can improve the severity of their UI following an in-home rehabilitation program, including the use of a mobile technology. This mode of delivery has the potential to address a gap in access to pelvic floor physiotherapy services for survivors of EC living in rural and remote communities.

The influence of contraction type, prior performance of a maximal voluntary contraction and measurement duration on fine-wire EMG amplitude.

We aimed to investigate the impact of time on fine-wire (fw) electromyography (EMG) signal amplitude, and to determine whether any attenuation is confounded by task type. Twenty healthy participants were instrumented with fw and surface (s) EMG electrodes at the biceps brachii bilaterally. Participants held a weight statically with one arm and with the other arm either repeated the same task following a maximum voluntary contraction (MVC) or repeated dynamic elbow flexion/extension contractions. Each task was repeated for 30 s every five minutes over two hours. EMG amplitude was smoothed and normalized to time = 0. Stable median power frequency of the s-EMG ruled out the confounding influence of fatigue. Repeated-measures ANCOVAs determined the effect of electrode type and time (covariate) on EMG amplitude and the confounding impact of task type. During the isometric protocol, fw-EMG amplitude reduced over time (p = 0.002), while s-EMG amplitude (p = 0.895) and MPF (p > 0.05) did not change. Fw-EMG amplitude attenuated faster during the dynamic than the isometric protocol (p = 0.008) and there was evidence that the MVC preceding the isometric protocol impacted the rate of decline (p = 0.001). We conclude that systematic signal attenuation of fw-EMG occurs over time and is more pronounced during dynamic tasks.

Reliability of ultrasound imaging of pelvic floor morphology and function among females who have undergone pelvic radiotherapy.

AIMS: To investigate the intra- and inter-rater reliability of two-dimensional (2D) transperineal ultrasound imaging (USI) measures of bladder wall thickness (BWT), urethral length (UL), and parameters related to levator plate length (LP) and transient changes in LP during pelvic floor muscle (PFM) contraction, and on Valsalva in women who received radiation therapy (RT) for treatment of pelvic cancer. METHODS: Twenty women with a history of RT for the treatment of pelvic cancer were assessed independently by two raters on the same day. Five outcomes were assessed for reliability: BWT, UL, and LP at rest (LP-R), during a maximal voluntary contraction of the PFMs (LP-MVC), and during a maximal-effort Valsalva maneuver (LP-MVM). Reliability was determined using intra-class correlation coefficients (ICC) and Bland-Altman analyses. Measurement error was determined using standard error of the measurement (SEM) and minimal detectable difference. RESULTS: Intra-rater reliability was very good for LP-R, LP-MVC, LP-MVM, and UL (ICC: 0.97 [0.93-0.99], 0.95 [0.88-0.98], 0.84 [0.59-0.94], and 0.96 [0.89-0.98], respectively). Inter-rater reliability was very good for LP-R (ICC: 0.82 [0.55-0.93]), and good for LP-MVC, LP-MVM, and UL (ICC: 0.79 [0.46-0.92], 0.79 [0.49-0.92], and 0.75 [0.36-0.90], respectively). BWT had poor intra- and inter-rater reliability. The variability between measurements was the smallest for LP-R, LP-MVC, and UL for intra-rater assessments, and for LP-R and UL for inter-rater assessments. SEM values for intra-rater assessments were LP-R: 1.5 mm, LP-MVC: 1.84 mm, LP-MVM: 4.33 mm, and UL: 1.16 mm. CONCLUSIONS: Although these results support the reliability of 2D-transperineal USI for the evaluation of UL and PFM parameters, they do not support its use for the assessment of BWT.

The pathophysiology of stress urinary incontinence: a systematic review and meta-analysis.

INTRODUCTION AND HYPOTHESIS: To evaluate the evidence for pathologies underlying stress urinary incontinence (SUI) in women. METHODS: For the data sources, a structured search of the peer-reviewed literature (English language; 1960-April 2020) was conducted using predefined key terms in PubMed and Embase. Google Scholar was also searched. Peer-reviewed manuscripts that reported on anatomical, physiological or functional differences between females with signs and/or symptoms consistent with SUI and a concurrently recruited control group of continent females without any substantive urogynecological symptoms. Of 4629 publications screened, 84 met the inclusion criteria and were retained, among which 24 were included in meta-analyses. RESULTS: Selection bias was moderate to high; < 25% of studies controlled for major confounding variables for SUI (e.g., age, BMI and parity). There was a lack of standardization of methods among studies, and several measurement issues were identified. Results were synthesized qualitatively, and, where possible, random-effects meta-analyses were conducted. Deficits in urethral and bladder neck structure and support, neuromuscular and mechanical function of the striated urethral sphincter (SUS) and levator ani muscles all appear to be associated with SUI. Meta-analyses showed that observed bladder neck dilation and lower functional urethral length, bladder neck support and maximum urethral closure pressures are strong characteristic signs of SUI. CONCLUSION: The pathology of SUI is multifactorial, with strong evidence pointing to bladder neck and urethral incompetence. While there is also evidence of impaired urethral support and levator ani function, standardized approaches to measurement are needed to generate higher levels of evidence.

Design and validation of an automated dual-arm instrumented intravaginal dynamometer.

AIMS: (1) To present the design of a novel intravaginal dynamometer (IVD) capable of measuring vaginal closure force on both the anterior and posterior arms, (2) to use bench testing to validate the force, speed of arm opening, and positional accuracy of load measurement along the IVD arms, and (3) to present in vivo force measurements made with this device, comparing forces measured by the anterior and posterior arms. METHODS: IVD load measurements were validated against an Instron® Universal Tester, arm opening speeds were validated using video analysis, and position-load accuracy was validated against calibration weights. In vivo IVD data were acquired from female volunteers during passive opening and pelvic floor muscle contraction tasks. Anterior and posterior IVD arm force outcomes were compared. RESULTS: Forces measured by the IVD and Instron® exhibited a strong linear relationship with excellent model fit. The speed control system was valid when tested under physiological loading conditions, however smaller antero-posterior opening diameters (25 and 30 mm) exhibited some error. The loading position along the IVD arms had no effect on force outcomes. In vivo data exhibited differences between force outcomes measured at the anterior and posterior aspects of the vagina during active contraction and passive elongation of the pelvic floor muscles. CONCLUSIONS: This IVD design demonstrates valid load measurement and speed control during bench testing. Active and passive forces measured are consistent with the literature. With dual instrumented arms, this device allows for further investigation into the source of measured vaginal closure forces.