Assessment of voluntary pelvic floor muscle contraction in continent and incontinent women using transperineal ultrasound, manual muscle testing and vaginal squeeze pressure measurements

The aims of the study were: (1) to assess women performing voluntary pelvic floor muscle (PFM) contractions, on initial instruction without biofeedback teaching, using transperineal ultrasound, manual muscle testing, and perineometry and (2) to assess for associations between the different measurements of PFM function. Sixty continent (30 nulliparous and 30 parous) and 60 incontinent (30 stress urinary incontinence (SUI) and 30 urge urinary incontinence (UUI)) women were assessed. Bladder neck depression during attempts to perform an elevating pelvic floor muscle (PFM) contraction occurred in 17% of continent and 30% of incontinent women. The UUI group had the highest proportion of women who depressed the bladder neck (40%), although this was not statistically significant (p=0.060). The continent women were stronger on manual muscle testing (p=0.001) and perineometry (p=0.019) and had greater PFM endurance (p<0.001) than the incontinent women. There was a strong tendency for the continent women to have a greater degree of bladder neck elevation than the incontinent women (p=0.051). There was a moderate correlation between bladder neck movement during PFM contraction measured by ultrasound and PFM strength assessed by manual muscle testing (r=0.58, p=0.01) and perineometry (r=0.43, p=0.01). The observation that many women were performing PFM exercises incorrectly reinforces the need for individual PFM assessment with a skilled practitioner. The significant correlation between the measurements of bladder neck elevation during PFM contraction and PFM strength measured using MMT and perineometry supports the use of ultrasound in the assessment of PFM function; however, the correlation was only moderate and, therefore, indicates that the different measurement tools assess different aspects of PFM function. It is recommended that physiotherapists use a combination of assessment tools to evaluate the different aspects of PFM function that are important for continence. Ultrasound is useful to determine the direction of pelvic floor movement in the clinical assessment of pelvic floor muscle function in a mixed subject population.     

Evaluation of Pelvic Floor Muscle Strength Using Four Different Techniques

The aim of the study was to evaluate whether four different techniques were able to correctly measure pelvic floor muscle strength only. Sixteen volunteers performed a set of muscle contractions using the pelvic floor muscles (PFM) only, the abdominal muscles with and without PFM, gluteal muscles with and without PFM, adductor muscles with and without PFM and Valsalva maneuver with and without PFM. Pelvic floor muscle strength was evaluated by digital palpation, intravaginal EMG, pressure perineometry and perineal ultrasound. A “non-pelvic muscle induced” reading was defined as a significant increase even though the pelvic floor muscles were not contracted. Results were as follows: isolated abdominal muscle contraction: non-pelvic muscle induced readings in 3/8 women with EMG and in 3/8 with pressure perineometry; isolated gluteal muscle contraction: non-pelvic muscle induced readings in 1/2 women with EMG perineometry; isolated adductor muscle contraction: non-pelvic muscle induced readings in 6/11 women with EMG perineometry and in 2/11 women with pressure perineometry; Valsalva maneuver: non-pelvic muscle induced readings in 4/9 women with EMG perineometry and 9/9 women with pressure perineometry. It was concluded that EMG and pressure perineometry do not selectively depict pelvic floor muscle activity.     

Assessment of pelvic floor movement using transabdominal and transperineal ultrasound

The aims of the study were (1) to assess the reliability of transabdominal (TA) and transperineal (TP) ultrasound during a pelvic floor muscle (PFM) contraction and Valsalva manoeuvre and (2) to compare TA ultrasound with TP ultrasound for predicting the direction and magnitude of bladder neck movement in a mixed subject population. A qualified sonographer assessed 120 women using both TA and TP ultrasound. Ten women were tested on two occasions for reliability. The reliability during PFM was excellent for both methods. TP ultrasound was more reliable than TA ultrasound during Valsalva. The percentage agreement between TA and TP ultrasound for assessing the direction of movement was 85% during PFM contraction, 100% during Valsalva. There were significant correlations between the magnitude of the measurements taken using TA and TP ultrasound and significant correlations with PFM strength assessed by digital palpation.     

Quantification of pelvic floor muscle strength in female urinary incontinence: A systematic review and comparison of contemporary methodologies

Aims

There remains no gold standard for quantification of voluntary pelvic floor muscle (PFM) strength, despite international guidelines that recommend PFM assessment in females with urinary incontinence (UI). Methods currently reported for quantification of skeletal muscle strength across disciplines are systematically reviewed and their relevance for clinical and academic use related to the pelvic floor are described.

Methods

A systematic review via Medline, PubMed, CINHAL, and the Cochrane database using key terms for pelvic floor anatomy and function were cross referenced with skeletal muscle strength quantification from 1946 to 2016. Full text peer‐reviewed articles in English having female subjects with incontinence were identified. Each study was analyzed for use of controls, type of methodology as direct or indirect measures, benefits, and limitations of the technique.

Results

A total of 1586 articles were identified of which 50 met the inclusion criteria. Nine methodologies of determining PFM strength were described including: digital palpation, perineometer, dynamometry, EMG, vaginal cones, ultrasonography, magnetic resonance imaging, urine stream interruption test, and the Colpexin pull test. Thirty‐two percent lacked a control group.

Conclusion

Technical refinements in both direct and indirect instrumentation for PFM strength measurement are allowing for sensitivity. However, the most common methods of quantification remain digital palpation and perineometry; techniques that pose limitations and yield subjective or indirect measures of muscular strength. Dynamometry has potential as an accurate and sensitive tool, but is limited by inability to assess PFM strength during dynamic movements.     

Postpartum impairment of pelvic floor muscle function: factors involved and association with prolapse

Introduction and hypothesis  

The aim of this study is to assess factors involved in the impairment of pelvic floor muscle (PFM) function from antepartum to 6 months postpartum. We also investigated whether reduced PFM strength was associated with pelvic organ prolapse (POP) postpartum.     

Test–retest reliability of internal pudendal artery blood flow using color Doppler ultrasound in healthy women

Introduction and hypothesis

The internal pudendal artery (IPA) is one of the main arteries supplying the pelvic floor muscles (PFMs) and vulvo-vaginal tissues. Its assessment with color Doppler ultrasound has been documented previously, but the reliability of IPA measurements has never been assessed. This study evaluates the test–retest reliability of IPA blood flow parameters measured by color Doppler ultrasound under two conditions: at rest and after a PFM contraction task.

Methods

Twenty healthy women participated in this study. One observer performed two measurement sessions using a clinical ultrasound system with a curved-array probe on the participant’s gluteal area. IPA measurements were repeated: at rest and after a PFM contraction task. Peak systolic velocity (PSV), time-averaged maximum velocity (TAMX), end-diastolic velocity (EDV), pulsatility index (PI), and resistance index (RI) were measured. Test–retest reliability was assessed using a paired t test, intraclass correlation coefficient (ICC), and Bland and Altman plots.

Results

There was no significant difference for all IPA blood flow measurements between the two repeated sessions. At rest, reliability was excellent for PSV and TAMX and the variability between measurements, as per Bland and Altman plots, was small. After PFM contractions, reliability was excellent for PSV and TAMX and fair to good for PI. The variability between measurements was small for PSV and acceptable for TAMX and PI. EDV and RI parameters did not perform as well.

Conclusion

The assessment of IPA blood flow with color Doppler ultrasound to evaluate vascular change in women is reliable.

     

Does a ring pessary in situ influence the pelvic floor muscle function of women with pelvic organ prolapse when tested in supine?

Introduction and hypothesis  

It has been suggested that repositioning pelvic organ prolapse (POP) by pessary support may improve pelvic floor muscle (PFM) function. The aim of the present study was to compare vaginal resting pressure and maximal voluntary contraction (MVC) of the PFM measured with and without a ring pessary in situ.     

Impact of levator trauma on pelvic floor muscle function

Introduction and hypothesis

Levator trauma is common after vaginal delivery, either as macrotrauma, i.e., levator avulsion, or microtrauma, i.e., irreversible overdistension of the levator hiatus. The effect of microtrauma on muscle function is unknown. We tested the hypothesis that levator trauma is associated with reduced contractile function of the levator ani.

Methods

Pregnant nulliparous women were recruited and seen before and after childbirth. All underwent an interview, a clinical examination including pelvic floor muscle (PFM) assessment using the Modified Oxford scale (MOS) [as an optional component] and translabial ultrasound. Sonographic and clinical parameters of PFM function were assessed before and after childbirth.

Results

Out of 560 women, 446 returned at a median of 5 months after childbirth and 433 were suitable for analysis. There was a significant reduction in all measures of PFM function except for MOS. Change in MOS was associated with delivery mode [analysis of variance (ANOVA) P?=?0.006). Forty-seven (15 %) vaginally parous women were diagnosed with levator avulsion, which was associated with a reduction in PFM contractility on sonographic parameters and MOS. However, only clinical assessment reached statistical significance. Sixty-five of 312 (21 %) women were diagnosed with microtrauma. We found no evidence of impairment in PFM contractility on ultrasound, but there was a statistically significant reduction in MOS.

Conclusions

Both levator avulsion (macrotrauma) and irreversible overdistension (microtrauma) are associated with reduced contractile function. This effect is more easily detected by palpation than by sonographic indices of levator function.     

Pelvic floor muscle strength in primigravidae and non-pregnant nulliparous women: a comparative study

Introduction and hypothesis

The objective was to evaluate the pelvic floor muscles (PFM) in primigravidae and compare them with those in nonpregnant nulliparous women.

Methods

The sample consisted of 141 women with a mean age of 22.8 years, divided into four groups: 36 nonpregnant nulliparous (C), 31 primigravidae in the first trimester (1T), 42 primigravida in the second trimester (2T), and 32 primigravidae in the third trimester (3T). The participants were examined by digital palpation for pelvic floor muscle contraction using the Modified Oxford Scale, by measuring maximal vaginal squeeze pressure with a vaginal perineometer, and by measuring PFM maximal strength using a vaginal dynamometer. The best value of three maximal strengths was considered for analysis, the Kruskal–Wallis and Mann–Whitney U tests were used and differences were considered significant at p?≤?0.05.

Results

The mean values for group C were 3.2 (digital palpation), 45.6 cmH₂O (perineometry), and 11.7 N (dynamometry); for group 1T the corresponding values were 2.5, 21.1 cmH₂O, and 8.8 N; for group 2T: 2.8, 22.9 cmH₂O, and 7.8 N; and for group 3T: 2.1, 17.3 cmH₂O, and 6.8 N. Groups were compared in pairs for digital palpation, perineometry, and dynamometry. There were significant differences between group C and group 1T, and between group C and group 3T. There was a significant difference between group C and group 2T with regard to perineometry and dynamometry, but not digital palpation. Dynamometry demonstrated a difference between groups 1T and 3T, digital palpation between groups 2T and 3T.

Conclusion

Pelvic floor muscles in primigravidae are not as strong as those in nonpregnant nulliparous women.

     

High prevalence of pelvic floor muscle dysfunction in hospitalized elderly women with urinary incontinence

Introduction and hypothesis

The purpose of this study was to determine pelvic floor muscle (PFM) function in hospitalized elderly women with urinary incontinence (UI).

Methods

A cross-sectional study was performed using data of 704 patients, routinely collected by means of a clinical UI assessment.

Results

Only 25.5% of the patients were able to perform normal PFM contractions (Oxford grading scale score ≥3); 74.5% were unable to contract their PFM or showed weak PFM activity without circular contraction or elevation of the vagina. Vulvovaginal mucosal dystrophy was noted in 84% of the patients. A significant positive correlation of PFM function was found to cognitive status (MMSE score), mobility (Tinetti performance score), and history of previous PFM training; a negative correlation of PFM function was found to patients’ age and vulvovaginal mucosal dystrophy, and no significant correlation to body mass index, parity, or history of hysterectomy.

Conclusions

Targeted clinical UI assessment including digital vaginal palpation should be performed in all incontinent elderly women in order to detect PFM dysfunction and to optimize therapeutic measures.     

Pelvic floor muscle function in women with pelvic floor dysfunction

Introduction and hypothesis

The objectives of this study were to investigate the level of pelvic floor muscle (PFM) function in women with pelvic floor dysfunction (PFD) referred by gynaecologists and urologists for in-hospital pelvic floor muscle training (PFMT), and to identity associated factors for a low level of PFM function.

Methods

Data of women with PFD referred to a PFMT programme were included in a retrospective chart review. Measurement of PFM function performed by digital vaginal palpation included: voluntary PFM contraction, PFM strength (Modified Oxford Grading Scale) and PFM static endurance.

Results

Data of 998 women, mean age 56 (SD 13) years, with PFD (urinary incontinence, n?=?757, anal incontinence, n?=?36, pelvic organ prolapse, n?=?111, other PFD, n?=?94) were analysed. In all, 690 women (70 %) were, at baseline, unable to perform correct voluntary PFM contraction, mean PFM strength was 1.5 (SD 1.0) points, mean PFM static endurance was 16.7 (SD 16.1) seconds. Age ≥ 65 years and year of referral > 2000 were significantly (p?< 0.01) associated with the ability to perform correct PFM contraction. Likewise, year of referral was significantly associated with high PFM strength (p?< 0.01).

Conclusions

The majority of the women were unable to perform correct voluntary PFM contraction and almost all had low PFM strength. The most important factor associated with a low level of PFM function was age.     

Ethnic differences in pelvic floor muscle strength and endurance in South African women

Introduction and hypothesis

Limited knowledge exists about pelvic floor muscle (PFM) function in ethnic groups. The aim of this study was to compare PFM strength and endurance in a group of black, white and mixed-race women.

Methods

This was a cross-sectional study. Maximum voluntary contraction (MVC) and endurance were measured with a perineometer and vaginal balloon sensor. Two sets of three MVC of the PFM were recorded; resting phase was 5 min. Demographic variables and factors associated with PFM strength were assessed.

Results

A total of 122 nulliparous black (n?=?44), white (n?=?44) and mixed-race (n?=?34) students participated. PFM of black women were stronger than that of white (p?=?0.02) or mixed-race (p?<?0.01) women. The MVC of PFM in black women decreased (p?=?0.02) between the first and second set of contractions.

Conclusions

Ethnic differences were found. Further clinical studies are needed to confirm an association between PFM function and pelvic floor disorders.     

Breathing with the pelvic floor? Correlation of pelvic floor muscle function and expiratory flows in healthy young nulliparous women

Introduction and hypothesis

The aim of this cross-sectional study was to determine correlations between pelvic floor muscle (PFM) function and expiratory function in healthy young nulliparous women.

Methods

In 40 volunteers, PFM function was assessed by vaginal palpation. Forced expiration patterns were evaluated visually and by palpation of the suprapubic insertion region of the anterolateral abdominal muscles. Forced vital capacity (FVC) and forced expiratory flows (FEF) were determined by spirometry.

Results

Incremental positive correlation was found between voluntary PFM contraction strength and forced expiratory flow at 25%, 50% and 75% (FEF_25%, FEF_50%, FEF_75%) of the FVC, respectively. Positive correlation was also found between PFM contraction strength and forced expired volume in 1 s (FEV₁). No correlation was found between PFM contraction strength and FVC or peak expiratory flow (PEF).

Conclusions

Despite some limitations of this study, the observed correlation between PFM contraction strength and forced expiratory flows may serve as theoretical background for a potential role of coordinated abdominal and PFM training in diseases with expiratory flow limitations.     

Comparison of transperineal and transabdominal ultrasound in the assessment of voluntary pelvic floor muscle contractions and functional manoeuvres in continent and incontinent women

Transperineal (TP) and transabdominal (TA) ultrasounds were used to assess bladder neck (TP) and bladder base (TA) movement during voluntary pelvic floor muscle (PFM) contraction and functional tasks. A sonographer assessed 60 asymptomatic (30 nulliparous, 30 parous) and 60 incontinent (30 stress, 30 urge) women with a mean age of 43 (SD = 7) years, BMI of 24 (SD = 4) kg m² and a median parity of 2 (range, 0–5), using both ultrasound methods. The mean of three measurements for bladder neck and bladder base (sagittal view) movement for each task was assessed for differences between the groups. There were no differences in bladder neck (p = 0.096) or bladder base (p = 0.112) movement between the four groups during voluntary PFM contraction but significant differences in bladder neck (p < 0.004) and a trend towards differences in bladder base (p = 0.068) movement during Valsalva and abdominal curl manoeuvre. During PFM contraction, there was a strong trend for the continent women to have greater bladder neck elevation (p = 0.051), but no difference in bladder base movement (p = 0.300), when compared to the incontinent women. The incontinent women demonstrated increased bladder neck descent during Valsalva and abdominal curl (p < 0.001) and bladder base descent during Valsalva (p = 0.021). The differences between the groups were more marked during functional activities, suggesting that comprehensive assessment of the PFM should include functional activities as well as voluntary PFM contractions. TP ultrasound was more reliable and takes measures from a bony landmark when compared to TA ultrasound, which lacks a reference point for measurements. TA ultrasound is less suitable for PFM measures during functional manoeuvres and comparisons between subjects. Few subjects were overweight so the results may not be valid in an obese population.     

Can the Paula method facilitate co-contraction of the pelvic floor muscles? A 4D ultrasound study

Introduction and hypothesis  

The aim was to compare constriction of the levator hiatus (LH) and reduction of pelvic floor muscle (PFM) length during instruction of the Paula method (contraction of ring musculature of the mouth) and contraction of the PFM.     

Comparison of pelvic muscle architecture between humans and commonly used laboratory species

Introduction and hypothesis

Pelvic floor muscles (PFM) are deleteriously affected by vaginal birth, which contributes to the development of pelvic floor disorders. To mechanistically link these events, experiments using animal models are required, as access to human PFM tissue is challenging. In choosing an animal model, a comparative study of PFM design is necessary, since gross anatomy alone is insufficient to guide the selection.

Methods

Human PFM architecture was measured using micromechanical dissection and then compared with mouse (n?=?10), rat (n?=?10), and rabbit (n?=?10) using the Architectural Difference Index (ADI) (parameterizing a combined measure of sarcomere length-to-optimal-sarcomere ratio, fiber-to-muscle-length ratio, and fraction of total PFM mass and physiological cross-sectional area (PCSA) contributed by each muscle). Coccygeus (C), iliocaudalis (IC), and pubocaudalis (PC) were harvested and subjected to architectural measurements. Parameters within species were compared using repeated measures analysis of variance (ANOVA) with post hoc Tukey’s tests. The scaling relationships of PFM across species were quantified using least-squares regression of log-10-transformed variables.

Results

Based on the ADI, rat was found to be the most similar to humans (ADI = 2.5), followed by mouse (ADI = 3.3). When animals’ body mass was regressed against muscle mass, muscle length, fiber length, and PCSA scaling coefficients showed a negative allometric relationship or smaller increase than predicted by geometric scaling.

Conclusion

In terms of muscle design among commonly used laboratory animals, rat best approximates the human PFM, followed by mouse. Negative allometric scaling of PFM architectural parameters is likely due to the multifaceted function of these muscles.     

Interobserver and interdisciplinary reproducibility of 3D endovaginal ultrasound assessment of pelvic floor anatomy

Introduction and hypothesis  

The study aims were to evaluate (1) the interobserver and (2) the interdisciplinary repeatability of levator hiatus, urethral thickness, and anorectal angle measurements using three-dimensional endovaginal ultrasound (3D-EVUS).     

An intra- and interrater reliability and agreement study of vaginal resting pressure,pelvic floor muscle strength,and muscular endurance using a manometer

Introduction and hypothesis

Manometry is commonly used to assess pelvic floor muscle (PFM) function. Aims of the study were to assess intra- and interrater reliability and agreement of vaginal resting pressure, PFM strength, and muscular endurance using a high-precision pressure transducer.

Methods

A convenient sample of 23 women was included. The participants were tested twice by two examiners on day 1 and retested after 1 week by one examiner. Vaginal resting pressure, PFM strength, and muscular endurance were measured by manometer (Camtech AS). Intraclass correlation coefficient (ICC) and Bland–Altman plots were used to analyze reliability and agreement respectively. Results are presented with mean differences (bias) and minimal detectable change.

Results

Twenty participants completed the tests (mean age 55.8 years [27–71], mean parity 1.7 [range 0–3], and mean body mass index 23.7 [range 18.4–27.2, SD 2.4]). ICC values were very good (ICC >0.90) for all measurements. Considerable intervariation of scores, and outliers were seen for measurements representing the highest values. Agreement with mean differences (bias) and minimal detectable change for the intrarater assessment was for vaginal resting pressure: ?2.44?±?8.7 cmH₂O, for PFM strength ?0.22?±?7.6 cmH₂O, and for muscular endurance 0.75?±?59.5 cmH₂O/s. The interrater agreement for vaginal resting pressure was: 1.36?±?9.0 cmH₂O, for PFM strength 2.24?±?9.0 cmH₂O, and for muscular endurance 15.89?±?69.7 cmH₂O/s.

Conclusions

Manometry (Camtech AS) seems less accurate for the strongest women. In clinical practice, significant improvement in PFM variables needs to exceed the minimal detectable change to be above the error of measurement.

     

Pelvic floor muscle function before and after first childbirth

Introduction and hypothesis  

Pregnancy and vaginal delivery are considered to be the main risk factors for development of pelvic floor dysfunction. We hypothesize that; 1) pelvic floor muscle (PFM) strength and endurance is significantly reduced by first delivery in general, and 2) changes in PFM strength and endurance are influenced by mode of delivery.     

Mechanisms of Pelvic Floor Muscle Function and the Effect on the Urethra during a Cough

Background

Current measurement tools have difficulty identifying the automatic physiologic processes maintaining continence, and many questions still remain about pelvic floor muscle (PFM) function during automatic events.

Objective

To perform a feasibility study to characterise the displacement, velocity, and acceleration of the PFM and the urethra during a cough.

Design, setting, and participants

A volunteer convenience sample of 23 continent women and 9 women with stress urinary incontinence (SUI) from the general community of San Francisco Bay Area was studied.

Measurements

Methods included perineal ultrasound imaging, motion tracking of the urogenital structures, and digital vaginal examination. Statistical analysis used one-tailed unpaired student t tests, and Welch's correction was applied when variances were unequal.

Results and limitations

The cough reflex activated the PFM of continent women to compress the urogenital structures towards the pubic symphysis, which was absent in women with SUI. The maximum accelerations that acted on the PFM during a cough were generally more similar than the velocities and displacements. The urethras of women with SUI were exposed to uncontrolled transverse acceleration and were displaced more than twice as far (p = 0.0002), with almost twice the velocity (p = 0.0015) of the urethras of continent women. Caution regarding the generalisability of this study is warranted due to the small number of women in the SUI group and the significant difference in parity between groups.

Conclusions

During a cough, normal PFM function produces timely compression of the pelvic floor and additional external support to the urethra, reducing displacement, velocity, and acceleration. In women with SUI, who have weaker urethral attachments, this shortening contraction does not occur; consequently, the urethras of women with SUI move further and faster for a longer duration.