Validity and reliability of an instrumented speculum designed to minimize the effect of intra-abdominal pressure on the measurement of pelvic floor muscle strength

Postpartum Changes in Levator Plate Shape and Genital Hiatus Size After Vaginal Delivery

INTRODUCTION AND HYPOTHESIS

Vaginal delivery is a risk factor for pelvic organ prolapse. We sought to quantify changes in level III pelvic support measurements at 7 weeks and 8 months following vaginal delivery.

METHODS

This secondary analysis included primiparous women who underwent pelvic MRI and clinical examinations at 7 weeks and 8 months after vaginal delivery. Demographics and obstetrical data were abstracted. Mid-sagittal resting MRIs were used to perform level III measurements including urogenital hiatus (UGH), levator hiatus (LH), and mid-sagittal levator area (LA), and to trace the levator plate (LP). Using principal component analysis, 7-week and 8-month principal component scores (PC1s) and MRI measurements were compared using paired t test. If the PC1 score change from 7 weeks to 8 months was > 0, women were considered to have a more dorsally oriented LP shape.

RESULTS

Of 76 participants, POP-Q values did not significantly differ between 7 weeks and 8 months, but MRI measurements improved (UGH: 3.9 ± 0.8 vs 3.5 ± 0.8, p < 0.001; LH: 5.4 ± 0.8 vs 5.2 ± 0.8, p = 0.01; LA: 18.0 ± 6.0 vs 15.2 ± 6.5, p < 0.001). Approximately 30% (22 out of 76) had a more dorsally oriented LP shape and larger level III measurements at 8 months than women with a more ventrally oriented LP shape (LA: 86.4% vs 1.9%, p < 0.001; LH: 16% vs 12%, p < 0.001; UGH: 59.1% vs 3.7%, p < 0.001).

CONCLUSIONS

After vaginal delivery, most women had "recovery" of level III support-defined by smaller UGH, LH, and LA measurements-and a more ventrally oriented LP shape. However, nearly 30% had larger level III measurements and a more dorsally oriented LP shape, indicating "impaired recovery" of support.

Objective Changes in Pelvic Floor Muscle Strength and Length in Women With High-Tone Pelvic Floor Dysfunction After Pelvic Floor Physical Therapy (RELAX Trial)

IMPORTANCE

Although pelvic floor physical therapy (PFPT) is effective in treating high-tone pelvic floor dysfunction (HTPFD), data on the mechanism of improvement are limited.

OBJECTIVES

This study aimed to compare squeeze intravaginal closure force after 6 weeks of PFPT in women affected by HTPFD and, secondarily, to describe changes in levator dimensions and short-term effects of PFPT on bladder, bowel, and pain symptoms.

METHODS

We conducted a prospective cohort study of patients undergoing 6 sessions of PFPT for the diagnosis of HTPFD. At baseline, we measured intravaginal closure force using an instrumented speculum, levator hiatal dimension using a 3-dimensional endovaginal ultrasonography, and symptom severity using 3 validated questionnaires. Intravaginal closure force and symptoms were reevaluated after the second, fourth, and sixth PFPT sessions, and levator hiatus was reevaluated at the sixth session.

RESULTS

Twenty-six women were enrolled and 22 completed 6 sessions and are included in the analysis. Contrary to our hypothesis, mean ± SD vaginal closure force (N) did not demonstrate a significant change (3.27 ± 2.34 vs 3.67 ± 2.02 N, P = 0.18). However, mean levator hiatal area (cm2) increased between visit 1 (13.71 ± 1.77 cm2) and visit 6 (14.43 ± 2.17 cm2, P = 0.05), as did the transverse diameter (3.83 ± 0.03 vs 3.95 ± 0.03 cm, P = 0.04). Survey responses demonstrated significant improvements across all measures of genitourinary symptoms, pain, lower gastrointestinal symptoms and quality-of-life measures after 6 sessions of PFPT.

CONCLUSION

Although the levator hiatal area increased after 6 sessions of PFPT (suggesting muscle lengthening), we were unable to demonstrate that this changed the force generated by pelvic floor muscles as measured by a speculum.

The state of pelvic floor muscle dynamometry: A scoping review

AIMS

To discuss the advantages and limitation of the different pelvic floor muscle (PFM) dynamometers available, both in research and industry, and to present the extent of variation between them in terms of structure, functioning, psychometric properties, and assessment procedures.

METHODS

We identified relevant studies from four databases (MEDLINE, Compendex, Web of Science, and Derwent Innovations Index) up to December 2020 using terms related to dynamometry and PFM. In addition, we conducted a hand search of the bibliographies of all relevant reports. Peer-reviewed papers, conference proceedings, patents and user's manuals for commercial dynamometers were included and assessed by two independent reviewers.

RESULTS

One hundred and one records were included and 23 PFM dynamometers from 15 research groups were identified. From these, 20 were considered as clinical dynamometers (meant for research settings) and three as personal dynamometers (developed by the industry). Overall, significant heterogeneity was found in their structure and functioning, which limits development of normative data for PFM force in women. Further research is needed to assess the psychometric properties of PFM dynamometers and to standardize assessment procedures.

CONCLUSION

This review points up to the heterogeneity of existing dynamometers and methods of assessing PFM function. It highlights the need to better document their design and assessment protocol methods. Additionally, this review recommends standards for new dynamometers to allow the establishment of normalized data.

A new 3D stress MRI measurement strategy to quantify surgical correction of prolapse in three support systems

AIMS

The aim of this study was to develop and test the feasibility of a magnetic resonance imaging (MRI)-based measurement strategy to evaluate the effectiveness of surgical procedures in restoring normal anatomy in all three systems of pelvic floor support and quantify the structural changes induced by prolapse surgery.

METHODS

Patients underwent clinical examination and stress MRI preoperatively and again 3 months postoperatively. Preoperative and postoperative measures of three MRI-based structural support systems were made: (1) vaginal wall, (2) apical and paravaginal support, and (3) hiatal closure system. Preoperative to postoperative structural changes were calculated and compared to normal values, and bivariate associations were determined.

RESULTS

The three structural support systems were successfully quantified for both preoperative and postoperative MRIs regardless of operative approaches in all 15 women in the pilot group. Apical support was restored to normal in 11 of 12 patients who underwent an apical suspension procedure and 9 of 14 patients with a posterior repair had normalization of genital hiatus size. Mid-vaginal paravaginal location was elevated an average of 2.5 ± 2.0 cm despite no paravaginal repairs being performed. Paravaginal location improvements were also significantly correlated with apical elevation (r values 0.99-0.87, p < 0.001).

CONCLUSIONS

A strategy that quantifies structural-specific preoperative impairments and improvements after prolapse surgery was successfully developed. Early findings reveal that prolapse surgery is more successful in restoring normal anatomy at Level I than Level III. Improvement in paravaginal location is significantly correlated with apical elevation.

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.

Mechanisms of hiatus failure in prolapse: a multifaceted evaluation

INTRODUCTION AND HYPOTHESIS

We investigated whether factors influencing pelvic floor hiatal closure are inter-related or independent, hypothesizing that (1) hiatus size is moderately correlated with levator defect, pelvic floor muscle strength, and change in hiatus size with contraction and (2) urogenital hiatus (UGH) and levator hiatus (LH) measures are similar in patients with anterior wall (AW) and posterior wall (PW) prolapse.

METHODS

This cross-sectional case-control study included subjects with AW prolapse (n = 50), PW prolapse (n = 50), and normal support (n = 50). Hiatus measurements and levator defects were assessed on MRI, and vaginal closure force was measured with an instrumented speculum. Pearson correlation coefficients and simple and multivariable linear regression models were performed.

RESULTS

During contraction, LH narrowed 47% more in the PW compared to AW group (p = 0.001). With straining, LH lengthened 34% more in the PW than AW group (p < 0.001). With straining, UGH and LH lengthening was greater by 72% and 44% in those with major compared to no/minor defect (p < 0.001 and p = 0.004). Contraction strength explained, at most, 4% of UGH (r = 0.17) or LH (r = 0.20) shortening during contraction (r = 0.17 and r = 0.20, respectively), indicating that these factors are largely independent. After controlling for prolapse size, resting UGH and levator defect status were associated with straining UGH (p < 0.001, p = 0.004), but muscle strength and resting tone were not.

CONCLUSIONS

Hiatus measures are complex and differ according to prolapse occurrence and type. They are, at best, only weakly correlated with pelvic floor muscle strength and movement during contraction.

A Dynamometer-based Wireless Pelvic Floor Muscle Force Monitoring

This paper covers the design and implementation of a proof of concept for a wireless system measuring pelvic floor muscle forces based on a dynamometer. The proposed device is the main component of a novel assessment tool intended for pelvic floor muscle rehabilitation in women suffering from urinary incontinence. The proposed system allows the physiotherapist to wirelessly monitor variation in pelvic floor muscle forces during assessment or training. Wireless communication is provided by a Bluetooth low energy transceiver and a corresponding interface designed for this purpose. Force measurements are sensed with strain gauge precision sensors operated in a Wheatstone bridge configuration. The designed module consumes 14 mW of power in operating mode. System design and experimental results are reported and discussed.

Do Measures of Muscular Fitness Modify the Effect of Intra-abdominal Pressure on Pelvic Floor Support in Postpartum Women?

OBJECTIVE

This study aimed to determine whether measures of muscular fitness modify the effect of intra-abdominal pressure (IAP) during lifting on pelvic floor support.

METHODS

Participants, primiparous women 1 year after vaginal delivery, underwent the Pelvic Organ Prolapse Quantification examination, measurement of IAP via a vaginal sensor while lifting a weighted car seat, pelvic floor muscle force assessment using an instrumented speculum, grip strength using a hand dynamometer, and trunk flexor endurance by holding an isometric contraction while maintaining a 60-degree angle to the table. We dichotomized pelvic floor support as worse (greatest descent of the anterior, posterior, or apical vagina during maximal strain at or below the hymen) versus better (all points above the hymen).

RESULTS

Of 825 participants eligible after delivery, 593 (71.9%) completed a 1-year study visit. Mean (SD) age was 29.6 (5.0) years. One year postpartum, 55 (9.3%) demonstrated worse support. There were no differences in IAP during lifting or in other measures of pelvic floor loading between women with better and worse support. In multivariable analyses, neither grip strength nor pelvic floor muscle force modified the effect of IAP on support. In women with trunk flexor endurance duration ≥13 minutes, the odds of worse support increased significantly as IAP increased. No fitness measure modified the effect of other measures of pelvic floor loading on support.

CONCLUSIONS

Primiparous women with higher IAP during lifting and greater muscular fitness did not have reduced odds of worse pelvic floor support compared with those with lower IAP at the same muscular fitness.

The Association Between Pelvic Floor Muscle Force and General Strength and Fitness in Postpartum Women

OBJECTIVE

The aim of the study was to determine whether measures of muscular strength and fitness are associated with pelvic floor muscle (PFM) force 1-year postpartum in a population of primiparous women who delivered vaginally.

METHODS

This cross-sectional analysis is an ancillary study to an ongoing prospective cohort study and includes 203 primiparous women. Procedures collected 1-year postpartum included maximal PFM force, grip strength, trunk flexor muscle endurance, percent body fat, intra-abdominal pressure during trunk flexor endurance testing, intra-abdominal pressure during strain, and self-reported physical activity.

RESULTS

The mean (SD) age was 29.8 (5.0) years and the mean (SD) body mass index was 24.5 (5.2) kg/m. Nineteen percent were of Hispanic ethnicity. The median (interquartile range) PFM force was 5.05 (2.86-7.94) N. The median (interquartile range) trunk flexor endurance time was 146.0 (78.0-267.0), whereas the mean (SD) grip strength and percent fat were 32.4 (6.4) kg and 29.4% (10.0), respectively.There were no statistically significant associations between PFM force and any of the measures tested on analyses unadjusted or adjusted for self-report of doing PFM exercises. Of other factors evaluated, non-Hispanic ethnicity, increasing age, self-reported family history of pelvic organ prolapse or urinary incontinence, and normal and obese body mass index (both compared with overweight) were associated with lower PFM force.

CONCLUSIONS

In primiparous women 1-year postpartum, we found no associations between PFM force and measures of strength and fitness. This study's results are consistent with existing literature that specific, targeted, and consistent pelvic floor exercises are the best way to improve PFM strength.

Reliability and Diagnostic Accuracy of a New Vaginal Dynamometer to Measure Pelvic Floor Muscle Strength

AIMS

Assess the intrarater and interrater reliabilities and diagnostic accuracy of a new vaginal dynamometer to measure pelvic floor muscle (PFM) strength in incontinent and continent women.

METHODS

A test-retest reliability study including 152 female patients.

EXCLUSION CRITERIA

history of urge urinary incontinence, prolapse of pelvic organ, pregnancy, previous urogynecological surgery, severe vaginal atrophy, or neurological conditions. The examination comprised digital assessment using the modified Oxford scale (MOS) and dynamometry measurements with a new prototype hand-held dynamometer. The MOS score ranges from 0 to 5: 0, no contraction; 1, flicker; 2, weak; 3, moderate; 4, good; 5, strong. Examinations were performed by a physiatrist, a physiotherapist and a midwife. The rest period between each rater measurement was 5 minutes. Assessment of intrarater and interrater reliability was calculated with the intraclass correlation coefficient.

RESULTS

One hundred twenty-two incontinent women and 30 continent women were included. Scores between 0 and 2 in MOS were recorded in 72% of incontinent women versus 20% in continent patients (P < 0.001). Intrarater reliability of the dynamometer was 0.942 (95% confidence interval [CI], 0.920-0.958) and the interrater reliability was 0.937 (95% CI, 0.913-0.954). The analysis of variance analysis showed significant differences in PFM strength across digital assessment categories. The post-hoc analysis showed statistical differences between adjacent categories of MOS 1-2 and 2-3. The diagnostic accuracy showed an area under the curve of 0.82 (95% C,: 0.75-0.89), 0.87 (95% CI, 0.81-0.92), and 0.83 (95% CI, 0.77-0.90) for the physiatrist, midwife, and physiotherapist, respectively.

CONCLUSIONS

The results obtained show a good reliability and validity of this new vaginal dynamometer to quantify PFM strength.

Intravaginal pressure profile of continent and incontinent women

A well-functioning pelvic floor muscle plays an important role in maintaining urinary continence. The aim of this study was to describe and compare the intravaginal pressure profile using a multisensor device along the vaginal length in women with and without urinary incontinence (UI), while performing pelvic floor muscle tasks. Fifty-four adult pre-menopausal women (31 continent and 23 incontinent) participated in this cross-sectional observational cohort study. The intravaginal pressure profile was assessed at rest, during maximum and sustained pelvic floor muscle contractions, using the Pliance® multisensor device. Between-group comparisons were performed considering the overall pressure and the pressure profile of 10-subregions along the vaginal length. In the overall pressure assessment, women with UI presented lower pressures at rest, similar pressures during maximum contraction and lower capacity to maintain pressure during sustained contraction compared to those in the continent group. The pressure profile assessment showed between-group differences that were consistent throughout tasks, with the incontinent group presenting lower pressures than the continent group, specifically in the mid-vaginal length, around 3-4 cm from the vaginal opening. We observed consistent deficits in pressure generation in incontinent compared to continent women, precisely in the region of the pelvic floor muscles. With this protocol and novel instrument, we obtained a reliable and consistent intravaginal pressure profile of continent and incontinent women. This approach could assist clinicians in the assessment of pelvic floor muscle function and foster a better understanding of the urinary incontinence mechanism.

Defining "normal recovery" of pelvic floor function and appearance in a high-risk vaginal delivery cohort

INTRODUCTION AND HYPOTHESIS

Childbirth pelvic floor trauma leads to pelvic floor disorders. Identification of significant injuries would facilitate intervention for recovery. Our objectives were to identify differences in pelvic floor appearance and function following delivery and patterns of normal recovery in women sustaining high-risk labor events.

METHODS

We completed a prospective cohort study comparing women undergoing vaginal births involving risk factors for pelvic floor injury with women undergoing cesareans. Data were collected on multidimensional factors including levator ani muscle (LA) tears. Descriptive and bivariate statistics were used to compare the groups. We identified potential markers of pelvic floor injury based on effect size.

RESULTS

Eighty-two women post-vaginal delivery and 30 women post-cesarean enrolled. The vaginal group had decreased perineal body length between early postpartum, 6 weeks (p < 0.001), and 6 months (p = 0.001). POP-Q points did not change between any time point (all p > 0.05). Measures of strength improved between each time point (all p < 0.002). When compared with cesarean delivery, women post-vaginal birth had longer genital hiatus and lower anterior and posterior vaginal walls (all p < 0.05). Based on theoretical considerations and effect sizes, those with Bp ≥0 cm, Kegel force ≤1.50 N, and/or an LA tear on imaging were considered to have significant pelvic floor injury. Using this definition, at 6 weeks, 27 (46.4%) women were classified as injured. At 6 months, 13 (29.6%) remained injured.

CONCLUSIONS

We propose that pelvic floor muscle strength, posterior vaginal wall support, and imaging consistent with LA tear are potential indicators of abnormal or prolonged recovery in this cohort with high-risk labor events.

Subsequent Use of a Pressure Sensor to Record Intra-Abdominal Pressure After Maximum Vaginal Closure Force in a Clinical Trial

Pelvic floor disorders are caused by weakening or damage to the tissues lining the bottom of the abdominal cavity. These disorders affect nearly 1 in every 4 women in the United States and symptoms that drastically diminish a patient’s quality of life. Vaginal closure force is a good measure of pelvic health, but current vaginal dynamometers were not designed for the rigors of hospital reprocessing, often failing due to sensor degradation through repeated sterilization processes. In order to obtain measurements of vaginal closure force in a large study, we designed a vaginal dynamometer that utilizes a removable intra-abdominal sensor already in production for the study. The sensor’s existing data acquisition system was modified to transmit to a tablet allowing the user to view data in real-time. The new speculum design allowed a single sensor to measure vaginal closure force before being used to collect intra-abdominal pressure data in the same study visit. The measurements taken with the new speculum were similar to measurements taken with a previously reported vaginal dynamometer.

A fiber-optic sensor-based device for the measurement of vaginal integrity in women

AIMS

Pelvic floor disorders (PFDs) in women are a major public health concern. Current clinical methods for assessing PFDs are either subjective or confounded by interference from intra-abdominal pressure (IAP). This study introduces an intravaginal probe that can determine distributed vaginal pressure during voluntary exercises and measures the degree of vaginal tissue support independent of IAP fluctuations.

METHODS

An intravaginal probe was fabricated with 18 independent fiber-optic pressure transducers positioned along its upper and lower blades. Continuous pressure measurement along the anterior and posterior vaginal walls during the automated expansion of the probe enabled the resistance of the tissue to be evaluated as a function of displacement, in a manner reflecting the elastic modulus of the tissue. After validation in a simulated vaginal phantom, in vivo measurements were conducted in the relaxed state and during a series of voluntary exercises to gauge the utility of the device in women.

RESULTS

The probe reliably detected variations in the composition of sub-surface material in the vaginal phantom. During in-vivo measurements the probe detected distributed tissue elasticity in the absence of IAP change. In addition, the distribution of pressure along both anterior and posterior vaginal walls during cough, Valsalva and pelvic floor contraction was clearly resolved with a large variation observed between subjects.

CONCLUSIONS

Our data highlight the potential for the probe to assess the integrity of the vagina wall and support structures as an integrated functional unit. Further in vivo trials are needed to correlate data with clinical findings to assist in the assessment of PFDs.

Aging effects on pelvic floor support: a pilot study comparing young versus older nulliparous women

INTRODUCTION AND HYPOTHESIS

We sought to determine age-related changes to the pelvic floor in the absence of childbirth effects.

METHODS

A case-control study was conducted from June 2017 to August 2018 comparing two groups of nulliparous women: <40 years old and ≥ 70 years old. Clinical evaluation included POP-Q, instrumented speculum testing, and handgrip strength. Dynamic 3D-stress MRI was performed on all women to obtain genital and levator hiatus (LH) lengths, LH area, and levator bowl volume. LH shape was quantified using a novel measure called the "V-U index." Pubovisceral muscle (PVM) cross-sectional area (CSA) was also measured. Bivariate comparisons between the two groups were made for all variables. Effect sizes were calculated for MRI measurements.

RESULTS

Twelve young and 9 older nulliparous women were included. Levator bowl volume at rest was 83% larger in older women (108.0 ± 34.5 cm³ vs 59.2 ± 19.3 cm³, p = 0.001, d = 1.82). MRI genital hiatus at rest was larger among the older group (2.7 ± 0.6 cm vs 3.5 ± 0.6 cm, p = 0.007, d = 1.34). V-U index, a measure of LH shape where 0 = "V" and 1 = "U," differed between groups indicating a more "U"-like shape among older women (0.71 ± 0.23 vs 0.35 ± 0.18, p = 0.001, d = 1.72). Handgrip strength was lower in the older vs young group (23.2 ± 5.2 N vs 33.4 ± 5.2 N, p < 0.0001); however, the Kegel augmentation force and PVM CSA were similar (3.2 ± 1.1 N vs 3.3 ± 2.2 N, p = 0.89, and 0.8 ± 0.3 cm² vs 0.7 ± 0.2 cm², p = 0.23 respectively).

CONCLUSIONS

Levator bowl volume at rest was over 80% larger among older women, reflecting a generalized posterior distension with age.

Clinical and MRI changes of puborectalis and iliococcygeus after a short period of intensive pelvic floor muscles training with or without instrumentation : A prospective randomized controlled trial

PURPOSE

This study evaluates the impact of a 3-week period of intensive pelvic floor muscles training (PFMT), with or without instrumentation, on clinical and static magnetic resonance imaging (MRI) changes of puborectalis (PR) and iliococcygeus (IL) muscles.

METHODS

24 healthy young women were enrolled in the study and 17 achieved the 9 sessions of 30 min training exercises and conducted all assessments. Participants were randomly assigned in two training groups: voluntary contractions combined with hypopressive exercises (HYPO) or biofeedback exercises combined with transvaginal electrical stimulations (ELEC). Clinical and T2-weighted MRI assessments were realized before and after training.

RESULTS

Modified Oxford Grading System (MOGS) scores for left PR and perineal body significantly increased in the two groups (p = 0.039, p = 0.008), but MOGS score for right PR significantly increased only in HYPO (p = 0.020). Muscle volumes of right and left IL significantly decreased (p = 0.040, p = 0.045) after training as well as signal intensities of right and left PR (p = 0.040, p = 0.021) and thickness of right and left IL at mid-vagina location (p = 0.012, p = 0.011).

CONCLUSIONS

A short period of intensive PFMT induces clinical and morphological changes in PFMs at rest suggesting a decrease in IL volume and adipose content of PR. Although the results suggested that an intensive non-instrumented PFMT is as effective as an instrumented training, future controlled studies with greater sample sizes are needed to establish the relative and absolute effectiveness of each of the two interventions.

High spatial resolution pressure distribution of the vaginal canal in Pompoir practitioners: A biomechanical approach for assessing the pelvic floor

BACKGROUND

Pompoir is a technique poorly studied in the literature that claims to improve pelvic floor strength and coordination. This study aims to investigate the pelvic floor muscles' coordination throughout the vaginal canal among Pompoir practitioners and non-practitioners by describing a high resolution map of pressure distribution.

METHODS

This cross-sectional, study included 40 healthy women in two groups: control and Pompoir. While these women performed both sustained and "waveform" pelvic floor muscle contractions, the spatiotemporal pressure distribution in their vaginal canals was evaluated by a non-deformable probe fully instrumented with a 10×10 matrix of capacitive transducers.

FINDINGS

Pompoir group was able to sustain the pressure levels achieved for a longer period (40% longer, moderate effect, P=0.04). During the "waveform" contraction task, Pompoir group achieved lower, earlier peak pressures (moderate effect, P=0.05) and decreased rates of contraction (small effect, P=0.04) and relaxation (large effect, P=0.01). During both tasks, Pompoir group had smaller relative contributions by the mid-region and the anteroposterior planes and greater contributions by the caudal and cranial regions and the latero-lateral planes.

INTERPRETATION

Results suggest that specific coordination training of the pelvic floor muscles alters the pressure distribution profile, promoting a more-symmetric distribution of pressure throughout the vaginal canal. Therefore, this study suggests that pelvic floor muscles can be trained to a degree beyond strengthening by focusing on coordination, which results in changes in symmetry of the spatiotemporal pressure distribution in the vaginal canal.

Effect of combined actions of hip adduction/abduction on the force generation and maintenance of pelvic floor muscles in healthy women

Pelvic floor muscle (PFM) force and coordination are related to urinary incontinence severity and to sexual satisfaction. Health professionals frequently combine classic PFM exercises with hip adduction/abduction contraction to treat these disorders, but the real benefits of this practice are still unknown. Based on a theoretical anatomy approach whereby the levator ani muscle is inserted into the obturator internus myofascia and in which force generated by hip movements should increase the contraction quality of PFMs, our aim was to investigate the effects of isometric hip adduction and abduction on PFM force generation. Twenty healthy, nulliparous women were evaluated using two strain-gauge dynamometers (one cylinder-like inside the vaginal cavity, and the other measuring hip adduction/abduction forces around both thighs) while performing three different tasks: (a) isolated PFM contraction; (b) PFM contraction combined with hip adduction (30% and 50% maximum hip force); and (c) PFM contraction combined with hip abduction (30% and 50% maximum hip force). Data were sampled at 100Hz and subtracted from the offset if existent. We calculated a gradient between the isolated PFM contraction and each hip condition (Δ Adduction and Δ Abduction) for all variables: Maximum force (N), instant of maximum-force occurrence (s), mean force in an 8-second window (N), and PFM force loss (N.s). We compared both conditions gradients in 30% and 50% by paired t-tests. All variables did not differ between hip conditions both in 30% and 50% of maximum hip force (p>.05). PFM contraction combined with isometric hip abduction did not increase vaginal force in healthy and nulliparous women compared to PFM contraction combined with isometric hip adduction. Therefore, so far, the use of hip adduction or abduction in PFM training and treatments are not justified for improving PFM strength and endurance.

Physical and cultural determinants of postpartum pelvic floor support and symptoms following vaginal delivery: a protocol for a mixed-methods prospective cohort study

INTRODUCTION

Pelvic floor disorders (PFDs), including pelvic organ prolapse (POP), stress and urgency urinary incontinence, and faecal incontinence, are common and arise from loss of pelvic support. Although severe disease often does not occur until women become older, pregnancy and childbirth are major risk factors for PFDs, especially POP. We understand little about modifiable factors that impact pelvic floor function recovery after vaginal birth. This National Institutes of Health (NIH)-funded Program Project, 'Bridging physical and cultural determinants of postpartum pelvic floor support and symptoms following vaginal delivery', uses mixed-methods research to study the influences of intra-abdominal pressure, physical activity, body habitus and muscle fitness on pelvic floor support and symptoms as well as the cultural context in which women experience those changes.

METHODS AND ANALYSIS

Using quantitative methods, we will evaluate whether pelvic floor support and symptoms 1 year after the first vaginal delivery are affected by biologically plausible factors that may impact muscle, nerve and connective tissue healing during recovery (first 8 weeks postpartum) and strengthening (remainder of the first postpartum year). Using qualitative methods, we will examine cultural aspects of perceptions, explanations of changes in pelvic floor support, and actions taken by Mexican-American and Euro-American primipara, emphasising early changes after childbirth. We will summarise project results in a resource toolkit that will enhance opportunities for dialogue between women, their families and providers, and across lay and medical discourses. We anticipate enrolling up to 1530 nulliparous women into the prospective cohort study during the third trimester, following those who deliver vaginally 1 year postpartum. Participants will be drawn from this cohort to meet the project's aims.

ETHICS AND DISSEMINATION

The University of Utah and Intermountain Healthcare Institutional Review Boards approved this study. Data are stored in a secure password-protected database. Papers summarising the primary results and ancillary analyses will be published in peer-reviewed journals.

Real-time measurement of the vaginal pressure profile using an optical-fiber-based instrumented speculum

Pelvic organ prolapse (POP) occurs when changes to the pelvic organ support structures cause descent or herniation of the pelvic organs into the vagina. Clinical evaluation of POP is a series of manual measurements known as the pelvic organ prolapse quantification (POP-Q) score. However, it fails to identify the mechanism causing POP and relies on the skills of the practitioner. We report on a modified vaginal speculum incorporating a double-helix fiber-Bragg grating structure for distributed pressure measurements along the length of the vagina and include preliminary data in an ovine model of prolapse. Vaginal pressure profiles were recorded at 10 Hz as the speculum was dilated incrementally up to 20 mm. At 10-mm dilation, nulliparous sheep showed higher mean pressures ( 102 ± 46 ?? mmHg ) than parous sheep ( 39 ± 23 ?? mmHg ) ( P = 0.02 ), attributable largely to the proximal (cervical) end of the vagina. In addition to overall pressure variations, we observed a difference in the distribution of pressure that related to POP-Q measurements adapted for the ovine anatomy, showing increased tissue laxity in the upper anterior vagina for parous ewes. We demonstrate the utility of the fiber-optic instrumented speculum for rapid distributed measurement of vaginal support.

Evaluating maternal recovery from labor and delivery: bone and levator ani injuries

OBJECTIVE

We sought to describe occurrence, recovery, and consequences of musculoskeletal (MSK) injuries in women at risk for childbirth-related pelvic floor injury at first vaginal birth.

STUDY DESIGN

Evaluating Maternal Recovery from Labor and Delivery is a longitudinal cohort design study of women recruited early postbirth and followed over time. We report here on 68 women who had birth-related risk factors for levator ani (LA) muscle injury, including long second stage, anal tears, and/or older maternal age, and who were evaluated by MSK magnetic resonance imaging at both 7 weeks and 8 months' postpartum. We categorized magnitude of injury by extent of bone marrow edema, pubic bone fracture, LA muscle edema, and LA muscle tear. We also measured the force of LA muscle contraction, urethral pressure, pelvic organ prolapse, and incontinence.

RESULTS

In this higher-risk sample, 66% (39/59) had pubic bone marrow edema, 29% (17/59) had subcortical fracture, 90% (53/59) had LA muscle edema, and 41% (28/68) had low-grade or greater LA tear 7 weeks' postpartum. The magnitude of LA muscle tear did not substantially change by 8 months' postpartum (P = .86), but LA muscle edema and bone injuries showed total or near total resolution (P < .05). The magnitude of unresolved MSK injuries correlated with magnitude of reduced LA muscle force and posterior vaginal wall descent (P < .05) but not with urethral pressure, volume of demonstrable stress incontinence, or self-report of incontinence severity (P > .05).

CONCLUSION

Pubic bone edema and subcortical fracture and LA muscle injury are common when studied in women with certain risk factors. The bony abnormalities resolve, but levator tear does not, and is associated with levator weakness and posterior-vaginal wall descent.