Pelvic floor muscle strength and thickness in continent and incontinent nulliparous pregnant women

Continence and pelvic floor status in nulliparous women at midterm pregnancy

INTRODUCTION AND HYPOTHESIS

A Cochrane review recommends antenatal pelvic floor muscle training (PFMT) in urinary incontinence (UI) prevention. The aim of the study was to investigate nulliparous pregnant women's knowledge about and practising of PFMT, their pelvic floor muscle (PFM) function, and ability to contract correctly. It was hypothesized that continent women had higher PFM strength and endurance than women with UI.

METHODS

Three hundred nulliparous women at gestational week 18-22 were included in a cross-sectional study. Vaginal resting pressure, maximum voluntary contraction, and PFM endurance were measured by manometer. UI was assessed by International Consultation on Incontinence Questionnaire Urinary Incontinence Short Form (ICIQ-UI-SF). Comparisons of PFM function in continent women and women with UI were analyzed using independent-samples t test. Mean differences with 95 % confidence interval (CI) are presented.

RESULTS

Of 300 women, 89 % had heard of PFMT at mid pregnancy, and 35 % performed PFMT once or more a week. After thorough instruction 4 % were unable to contract correctly. Thirty-five percent reported UI, of whom 48 % performed PFMT once or more a week. Continent women had significantly higher PFM strength and endurance when compared with women having UI, with mean differences of 6.6 cmH(2)O (CI 2.3-10.8, p = 0.003), and 41.5 cmH(2)Osec (CI 9.8-73.1, p = 0.010), respectively. No difference was found for vaginal resting pressure (p = 0.054).

CONCLUSIONS

Most nulliparous pregnant women knew about PFMT. Thirty-five percent performed PFMT once or more a week. Incontinent nulliparous pregnant women had weaker PFM than their continent counterparts. More emphasis on information regarding PFM function and PFMT is warranted during pregnancy.

Electromyographic evaluation of pelvic floor muscles in pregnant and nonpregnant women

INTRODUCTION AND HYPOTHESIS

We compared the maximal voluntary contraction (MVC) and strength of pelvic floor muscles (PFM) of pregnant and nonpregnant women using surface electromyography (SEMG).

METHODS

Fifteen pregnant primiparous women and 15 nulliparous nonpregnant women were evaluated. The healthy pregnant women were in the third trimester of pregnancy with a single fetus and did not have any neuromuscular alterations. The nonpregnant women did not present with PF dysfunctions and, as with the pregnant women, did not have any previous gynecological surgeries or degenerative neuromuscular alterations. The evaluation methods used were digital palpation (Oxford Grading Scale, which ranges from 0 to 5) and SEMG. In the EMG exam, MVC activity was evaluated, and the better of two contractions was chosen. Before the evaluation, all women received information about PFM localization and function and how to correctly contract PFM.

RESULTS

In the EMG evaluation, MVC was significantly greater in the nonpregnant group (90.7 μv) than in the pregnant group (30 μv), with p < 0.001. The same results were observed after vaginal palpation, measured by the Oxford scale, which presented an average of 2.1 in the pregnant group and 4.5 in the nonpregnant group (p = 0.005).

CONCLUSION

In comparison to nulliparous women, pregnant women demonstrated worse PFM function with decreased strength and electrical activity.

Effect of pelvic-floor muscle strengthening on bladder neck mobility: a clinical trial

BACKGROUND

Pelvic-floor muscle (PFM) strengthening has been widely used to treat people with urinary incontinence (UI). However, its effect on bladder neck position and stiffness is unknown.

OBJECTIVE

The aim of the study was to investigate the effect of PFM strengthening on bladder neck mobility for women with stress UI (SUI) or mixed UI (MUI).

DESIGN

This study was conducted as a single-group pretest-posttest design.

SETTING

This study was conducted mainly at the Life Quality & Health Promotion Laboratory at National Taiwan University and partly in the Ultrasonography Room of the Department of Obstetrics and Gynecology at National Taiwan University Hospital. Patients Twenty-three patients (mean age=51.9 years, SD=6.1) participated in the study.

INTERVENTION AND MEASUREMENTS

Each participant underwent a PFM strengthening program for 4 months. Bladder neck position at rest and during a cough, the Valsalva maneuver, and a PFM contraction was assessed by transperineal ultrasonography before and after the intervention. Severity Index score, self-reported improvement, PFM strength (force-generating capacity), and vaginal squeeze pressure were assessed for treatment effect.

RESULTS

The position of the bladder neck at PFM contraction and bladder neck mobility for maximal incursion from rest to PFM contraction were elevated, with effect sizes of 0.48 and 0.84, respectively. Bladder neck position and bladder neck mobility were not changed during a cough and the Valsalva maneuver. All participants reported diminution of incontinence, and PFM strength and maximal vaginal squeeze pressure were improved after the intervention. Limitations The limitations of the present trial included the pretest-posttest design and the absence of intra-abdominal pressure measuring and exercise adherence recording.

CONCLUSIONS

Four months of daily PFM strengthening can significantly improve the ability of the PFM to elevate the bladder neck voluntarily, but may not improve its stiffness during a cough and the Valsalva maneuver for women with SUI and MUI.

Ultrasound imaging of the pelvic floor: where are we going?

We produced a non systematic review of ultrasound imaging of the pelvic floor in women with urinary incontinence (UI) and/or pelvic organ prolapse (POP). We have searched the PubMed and Embase databases for the following PICO question: women; imaging; urinary incontinence, pelvic organ prolapse, pelvic floor, pelvic floor muscle, pelvic floor muscle training; physical examination, no imaging; diagnosis, prognosis, outcome. The production of a systematic review was deemed impossible based on the type and quality of the published evidence. Clinical research focused on the pathophysiology of the UI and POP looking relation between anatomic abnormalities, childbirth, the risk of UI or POP, the outcome of conservative treatment and reconstructive surgery. Published papers fall into the remits of diagnostic studies but often fail to comply with the recommendations of the STARD initiative. Most published evidence remains the product of a single institution effort and confirmatory studies are rarely found. Imaging studies in patients with UI did not provide evidence of any clinical benefit in the management of patients. In patients with POP, interesting correlations have been identified such as between childbirth, dimension of levator hiatus, avulsion of levator ani and risk of prolapse, but the non clinical benefit of pelvic floor imaging could still not be identified. Research on pelvic floor imaging requires a coordinated, international, multicentre effort to improve internal and external validity of imaging techniques, confirm observations published by single institutions and provide health technology assessment of imaging in the management of UI or POP patients.

Ultrasound imaging transducer motion during clinical maneuvers: respiration, active straight leg raise test and abdominal drawing in

Clinical use of ultrasound imaging by physiotherapists is increasing; however, the clinical setting may be problematic due to variability inherent in the environment. As transducer motion interferes with accurate measurement, this study aimed to measure handheld transducer motion, relative to the pelvis, during a clinical simulation involving typical maneuvers employed in a physiotherapy assessment of the lumbopelvic region. Transducer motion about three axes and through one plane was measured (Vicon, Oxford, UK) on 12 participants during three clinical maneuvers at four abdominal imaging sites. Data were grouped and means used to determine discrepancies in transducer and pelvic motion for each imaging site/maneuver combination. None of the conditions produced large transducer motions relative to the pelvis and all findings were within previously established guidelines for acceptable amounts of transducer motion. These findings suggest that an ultrasound transducer can be held relatively stationary in a clinical setting, for the maneuvers tested.

Evidence for benefit of transversus abdominis training alone or in combination with pelvic floor muscle training to treat female urinary incontinence: A systematic review

AIMS

Pelvic floor muscle training (PFMT) has Level A evidence to treat female urinary incontinence (UI). Recently, indirect training of the pelvic floor muscles (PFM) via the transversus abdominis muscle (TrA) has been suggested as a new method to treat UI. The aim of this article is to discuss whether there is evidence for a synergistic co-contraction between TrA and PFM in women with UI, whether TrA contraction is as effective, or more effective than PFMT in treating UI and whether there is evidence to recommend TrA training as an intervention strategy.

METHODS

A computerized search on PubMed, and hand searching in proceedings from the meetings of the World Confederation of Physical Therapy (1993-2007), International Continence Society and International Urogynecology Association (1990-2007) were performed.

RESULTS

While a co-contraction of the TrA normally occurs with PFM contraction, there is evidence that a co-contraction of the PFM with TrA contraction can be lost or altered in women with UI. No randomized controlled trials (RCTs) were found comparing TrA training with untreated controls or sham. Two RCTs have shown no additional effect of adding TrA training to PFMT in the treatment of UI.

CONCLUSIONS

To date there is insufficient evidence for the use of TrA training instead of or in addition to PFMT for women with UI. Neurourol. Urodyn. 28:368-373, 2009. (c) 2009 Wiley-Liss, Inc.

Influence of pelvic floor muscle contraction on the profile of vaginal closure pressure in continent and stress urinary incontinent women

PURPOSE

We characterized the vaginal pressure profile as a representation of closure forces along the length and circumference of the vaginal wall. Vaginal pressure profile data were used to test the hypothesis that the strength of pelvic floor muscle contractions differs significantly between continent women and women with stress urinary incontinence.

MATERIALS AND METHODS

Vaginal pressure profile recordings were made in 23 continent subjects and in 10 patients with stress urinary incontinence. The recordings characterized closure forces along the entire length of the vagina and identified differences among the anterior, posterior, left and right sides of the vaginal wall. Using a novel, directionally sensitive vaginal probe we made vaginal pressure profile measurements with the women at rest and during pelvic floor muscle contraction while supine.

RESULTS

The nature of the vaginal pressure profile was characterized in terms of force distribution in the anterior and posterior vaginal walls, which was significantly greater than that on the left and right sides. The continent group had significant greater maximum pressure than the stress urinary incontinence group on the posterior side at rest (mean +/- SE 3.4 +/- 0.3 vs 2.01 +/- 0.36 N/cm(2)) and during pelvic floor muscle contraction (4.18 +/- 0.26 vs 2.25 +/- 0.41 N/cm(2)). The activity pressure difference between the posterior and anterior vaginal walls in the continent group was significantly increased when the pelvic floor muscles contracted vs that at rest (3.29 +/- 0.21 vs 2.45 +/- 0.26 N/cm(2)). However, the change observed in the stress urinary incontinence group was not significant (1.85 +/- 0.38 vs 1.35 +/- 0.27 N/cm(2)).

CONCLUSIONS

The results demonstrate that the voluntary pelvic floor muscles impose significant closure forces along the vaginal wall of continent women but not in women with stress urinary incontinence. The implication of these findings is that extrinsic urethral closure pressure is insufficiently augmented by pelvic floor muscle contraction in women with stress urinary incontinence.

Is balance different in women with and without stress urinary incontinence?

AIMS

This study investigated whether there are differences in center of pressure (COP) displacement, trunk motion, and trunk muscle activity in women with and without stress urinary incontinence (SUI) during static balance tasks when the bladder is empty and moderately full.

METHODS

Subjects stood on a force plate during six static balance conditions: eyes open, eyes closed, standing on foam with eyes open, standing on foam with eyes closed, tandem stance, and standing on a short base. Electromyographic activity (EMG) of the pelvic floor (PF), abdominal, and erector spinae muscles were recorded using surface electrodes. Motion of the lumbar spine, pelvis, and hips was measured with four inclinometers. Trials were performed with the bladder empty, and when the subject reported a sensation of moderate bladder fullness after drinking 250-1,000 ml of water.

RESULTS

Women with SUI had greater COP displacement (range and root mean square), and increased trunk muscle EMG during static balance tests compared to continent women. When tasks were performed with the bladder moderately full, COP displacement and abdominal muscle EMG were increased in both groups.

CONCLUSIONS

This study demonstrates that women with SUI have decreased balance ability compared to continent women. Increased activity of the PF and trunk muscles in women with SUI may impair balance as a result of a reduced contribution of trunk movement to postural correction or compromised proprioceptive acuity. As compromised balance has been linked to falls risk, further research into balance deficits and falls prevalence in this population is warranted.

Rehabilitative ultrasound imaging: understanding the technology and its applications

The use of ultrasound imaging by physical therapists is growing in popularity. This commentary has 2 aims. The first is to introduce the concept of rehabilitative ultrasound imaging (RUSI), provide a definition of the scope of this emerging tool in regard to the physical therapy profession, and describe how this relates to the larger field of medical ultrasound imaging. The second aim is to provide an overview of basic ultrasound imaging and instrumentation principles, including an understanding of the various modes and applications of the technology with respect to neuromusculoskeletal rehabilitation and in relation to other common imaging modalities.

Rehabilitative ultrasound imaging of pelvic floor muscle function

This commentary provides an overview of the current concepts and evidence related to rehabilitative ultrasound imaging of pelvic floor (levator ani) function. As this is an emerging topic, the goal is to provide a basic understanding of ultrasound imaging applications related to levator ani function: the available quantitative and qualitative information, the limitations, as well as how ultrasound imaging can be incorporated as a form of biofeedback during rehabilitation. Furthermore, as the ability to compile and compare existing evidence depends on the degree of similarity in methodology by investigators, this commentary highlights points of consideration and provides guidelines, as well as an agenda, for future investigation.

Cystometric urine stream interruption test in women with urodynamic stress incontinence

Urine stream interruption test (UST) is one of the subjective means of assessing pelvic floor muscle strength. This is done with the belief that most women with stress urinary incontinence cannot interrupt the flow of urine stream due to weak pelvic floor muscles. It is also used by some to monitor pelvic floor muscle strength following treatment. Our study looked at a cohort of 104 women with stress urinary incontinence and to our knowledge, our study is the first to use UST in women who have had their stress urine incontinence confirmed on urodynamics. We found that 87% of those with urodynamic stress incontinence (USI) were able to perform this test (UST). We therefore concluded that UST is a poor index of pelvic floor muscle function in women with USI and cannot be relied upon to monitor success of treatment in these women.

Force and stiffness of the pelvic floor as function of muscle length: A comparison between women with and without stress urinary incontinence

AIMS

To compare passive and active mechanical properties in the pelvic floor as a function of tissue length in continent and incontinent parous women.

MATERIALS AND METHODS

Twenty-four parous continent and 21 parous incontinent women were examined with an intravaginal device. Passive and active force/stiffness were measured by increasing the transverse diameter of the vagina. To allow a more accurate comparison between groups, measured forces were normalized with respect to bodyweight, that is, force/bodyweight.

RESULTS

In both groups passive and active forces increased as a function of the increase in length of the pelvic floor tissues. No difference was found between the groups according to passive forces (P = 0.646), but active force was significantly higher (P = 0.030) in the continent group when normalized for bodyweight. There was an almost linear increase in normalized passive stiffness in the range tested. No differences were found between the groups (P = 0.855). Normalized active stiffness was significantly reduced in the incontinent group (P = 0.021).

CONCLUSIONS

This study indicates that both active force development and active stiffness in the pelvic floor tissues are significantly reduced in incontinent women, whereas the passive resting mechanical forces in the pelvic floor tissues in both groups are not different.

Postural response of the pelvic floor and abdominal muscles in women with and without incontinence

AIMS

To determine whether activity of the pelvic floor (PF) and abdominal muscles differs between continent and incontinent women in response to a postural perturbation with a moderately full or empty bladder.

METHODS

Electromyographic (EMG) activity of the PF and abdominal muscles was recorded with surface electrodes prior to and after a postural perturbation in which a 1 kg weight was dropped 30 cm into a bucket held by the subject. Perturbations were applied to the trunk in trials in which the timing of the weight drop was unknown (unexpected) or predictable (expected). Trials were performed with the bladder empty, and when the subject reported a sensation of moderate bladder fullness after drinking between 200 and 1,000 ml of water.

RESULTS

Women with incontinence demonstrated increased PF EMG compared to continent women both prior to and during the postural response associated with unexpected loading. In addition, obliquus externus abdominis EMG was increased in incontinent women during these trials. When the bladder was moderately full, PF EMG decreased, whereas abdominal muscle EMG tended to increase.

CONCLUSIONS

These data suggest that women with incontinence have increased PF and abdominal muscle activity associated with postural perturbations. This finding challenges the clinical assumption that incontinence is associated with reduced PF muscle activity, and suggests that training control and coordination of abdominal muscle activity may be important in treatment of this condition. The contrasting effects of increased bladder volume on PF and abdominal muscle EMG are likely to present further challenges to the maintenance of continence.

Postural activity of the pelvic floor muscles is delayed during rapid arm movements in women with stress urinary incontinence

The aim of this study was to determine whether postural activity of the pelvic floor (PF) and abdominal muscles differs between continent and incontinent women during rapid arm movements that present a postural challenge to the trunk. A further aim was to study the effect of bladder filling. Electromyographic activity (EMG) of the PF, abdominal, erector spinae (ES), and deltoid muscles was recorded with surface electrodes. During rapid shoulder flexion and extension, PF EMG increased before that of the deltoid in continent women, but after the deltoid in incontinent women (p = 0.002). In many incontinent women, PF EMG decreased before the postural activation. Although delayed, postural PF EMG amplitude was greater in women with incontinence (p = 0.010). In both groups, PF EMG decreased and abdominal and ES EMG increased when the bladder was moderately full. These findings would be expected to have negative consequences for continence and lumbopelvic stability in women with incontinence.

Sitting posture affects pelvic floor muscle activity in parous women: an observational study

QUESTION

Do different sitting postures require different levels of pelvic floor and abdominal muscle activity in healthy women?

DESIGN

Observational study.

PARTICIPANTS

Eight parous women with no pelvic floor dysfunction.

OUTCOME MEASURES

Bilateral activity of pelvic floor muscles (assessed vaginally) and two abdominal muscles, obliquus internus abdominis and obliquus externus abdominis, during three sitting postures.

RESULTS

There was a significant increase in pelvic floor muscle activity from slump supported sitting (mean 7.2% maximal voluntary contraction, SD 4.8) to both upright unsupported sitting (mean 12.6% maximal voluntary contraction, SD 7.8) (p = 0.01) and very tall unsupported sitting (mean 24.3% maximal voluntary contraction, SD 14.2) (p = 0.004). Activity in both abdominal muscles also increased but did not reach statistical significance.

CONCLUSION

Both unsupported sitting postures require greater pelvic floor muscle activity than the supported sitting posture.

Biometry of the pubovisceral muscle and levator hiatus in nulliparous Chinese women

OBJECTIVES

To identify using three-dimensional (3D) ultrasound the morphological features and normal biometry of the levator hiatus in nulliparous Chinese women and to explore ethnic differences between these measurements and those in nulliparous Caucasian women.

METHODS

3D sonographic data from 59 nulliparous Chinese women (aged 19-38 years) who had no pelvic organ prolapse and no symptoms of pelvic floor dysfunction were retrieved from an image dataset and analyzed by offline post-processing. The pubovisceral muscle and levator hiatus were measured in the planes of maximal pubovisceral muscle thickness and minimum hiatal dimension, respectively. In addition, the genitohiatal and levator ani angles were measured. These values were compared with those in a published study of Caucasian women.

RESULTS

In Chinese women there was no relationship between minimum anteroposterior (AP) hiatal diameter and minimum lateral hiatal diameter. Body weight was correlated with hiatal area and minimum AP hiatal diameter (r = 0.391, P = 0.003 and r = 0.378, P = 0.004, respectively), whereas body mass index was correlated only with minimum AP hiatal diameter (r = 0.349, P = 0.008). There was a significant difference in average pubovisceral muscle thickness (P = 0.001) between nulliparous Chinese and Caucasian women.

CONCLUSIONS

Body weight, body mass index, and ethnicity are factors affecting the biometry of the levator hiatus in Chinese nulliparous women.

Urinary incontinence symptoms during and after pregnancy in continent and incontinent primiparas

OBJECTIVE

Examine patterns of urinary incontinence during and after pregnancy, as recalled by incontinent and continent primiparas.

STUDY DESIGN

Primiparous women reporting no pre-pregnancy incontinence, were recruited 6 to 9 months postpartum. Those reporting current continence and demonstrating a negative stress test were considered "Primiparous Continent" (PC, n=64). Those reporting current incontinence and demonstrating a positive stress test were considered "Primiparous Incontinent" (PI, n=57). Subjects self-administered a questionnaire recalling leakage during and after pregnancy.

RESULTS

Sixteen percent of PC women leaked during pregnancy. Of these, 70% experienced frequent leakage during pregnancy. Seventy-eight percent of PI women leaked both during and after pregnancy. Several patterns arose surrounding leakage frequency for PI women: 19% only leaked frequently during pregnancy, 4% only leaked frequently after pregnancy, and 51% leaked frequently both during and after pregnancy.

CONCLUSION

Nearly five times as many primiparous incontinent women, compared with primiparous continent women, leaked during pregnancy.

Pelvic floor muscle evaluation in incontinent patients

The aim of this study was to assess pelvic floor muscle (PFM) strength and perception and its correlation with stress urinary incontinence (SUI). One hundred and one women were divided into two groups according to the presence (G1=51 patients) or absence (G2=50 patients) of SUI. Subjective [urine stream interruption test (UST), visual survey of perineal contraction and transvaginal digital palpation to assess pelvic muscle contraction] and objective evaluations of pelvic floor muscles in all patients were performed (vaginal manometry). During the UST, 25.5% of G1 patients and 80% of G2 patients were able to interrupt the urine stream (p<0.05). Digital evaluation of pelvic muscular contraction showed higher strength in G2 than in G1 patients (p<0.0001). Perineometer evaluation of PFM strength was significantly higher in the continent group (p<0.001). Pelvic floor muscle weakness in incontinent patients demonstrates the importance of functional and objective evaluation of this group of muscles.