Needle emg registration of striated urethral wall and pelvic floor muscle activity patterns during cough,valsalva, abdominal,hip adductor,and gluteal muscle contractions in nulliparous healthy females

The aim of the present study was to describe co-activity patterns of the striated urethral wall muscle and the pelvic floor muscles (PFM) during contraction of outer pelvic muscles. Six healthy nulliparous physical education students, mean age 19.5 years (19–21) participated in the study. Concentric needle EMG and a Dantec amplifier were used for registrations. EMG activity was continuously recorded with the participants lying in a supine position. EMG was recorded during relaxation, contraction of the PFM. valsalva maneuver, coughing, hip adductor contraction, gluteal muscle contraction, backward tilting of the pelvis, and sit-ups. The procedure was performed with the needle in the striated muscle of the anterior wall of the urethra and then repeated with the needle set lateral to the urethra in the PFM. The results showed that the striated urethral wall muscle was contracted synergistically during PFM, hip adductor, and gluteal muscle contraction, but not during abdominal contraction. Both hip adduction, gluteal muscle, and abdominal muscle contraction gave synergistic contraction of the PFM. Thus the urethral wall striated muscle and the PFM react differently during abdominal contraction. © 1994 Wiley-Liss, Inc.     

Differences in muscle activation patterns during pelvic floor muscle contraction and Valsalva maneuver

AIMS: To investigate the different muscle activation patterns around the abdomino-pelvic cavity in continent women and their effect on pressure generation during a correct pelvic floor muscle (PFM) contraction and a Valsalva maneuver. METHODS: Thirteen continent women were assessed. Abdominal, chest wall, and PFM activity and vaginal and intra-abdominal pressure (IAP), were recorded during two tasks: PFM contraction and Valsalva whilst bladder base position was monitored on trans-abdominal ultrasound. A correct PFM contraction was defined as one that resulted in bladder base elevation and a Valsalva resulted in bladder base depression. RESULTS: Comparison of the mean of the normalized EMG activity of all the individual muscle groups was significantly different between PFM contraction and Valsalva (P = 0.04). During a correct PFM contraction, the PFM were more active than during Valsalva (P = 0.001). During Valsalva, all the abdominal muscles (IO (P = 0.006), EO (P < 0.001), RA (P = 0.011)), and the chest wall (P < 0.001) were more active than during PFM contraction. The change in IAP was greater during Valsalva (P = 0.001) but there was no difference in the change in vaginal pressure between PFM contraction and Valsalva (P = 0.971). CONCLUSIONS: This study demonstrates a difference in muscle activation patterns between a correct PFM contraction and Valsalva maneuver. It is important to include assessment of the abdominal wall, chest wall, and respiration in the clinical evaluation of women performing PFM exercises as abdominal wall bracing combined with an increase in chest wall activity may cause rises in IAP and PFM descent.     

Altered muscle activation patterns in symptomatic women during pelvic floor muscle contraction and Valsalva manouevre

AIMS: To investigate the muscle activation patterns of the abdomino-pelvic region used by incontinent women during a pelvic floor muscle (PFM) contraction and a Valsalva manouevre compared to healthy, asymptomatic subjects. METHODS: Thirteen incontinent (symptomatic) women, identified using ultrasound to be consistently depressing the bladder base during PFM contraction, and thirteen continent women (asymptomatic) able to perform an elevating PFM contraction were assessed using surface electromyography (EMG) of the PFM, abdominal and chest wall muscles and vaginal and intra-abdominal pressure (IAP) measurements during PFM contraction and Valsalva under ultrasound surveillance. RESULTS: There were no differences between groups in age, parity or BMI. There was a difference in muscle activation patterns between groups (P = 0.001). During PFM contraction the PFM were less active and the abdominal and chest wall muscles were more active in the symptomatic group. During Valsalva, the PFM and EO were more active in the symptomatic group but there was no difference in the activation of the other muscles between groups. There was a significant interaction (group x pressure) for change in IAP (P = 0.047) but no significant interaction for change in vaginal pressure (VP) (P = 0.324). CONCLUSIONS: The symptomatic women displayed altered muscle activation patterns when compared to the asymptomatic group. The symptomatic women were unable to perform a voluntary PFM contraction using a localized muscle strategy, instead activating all the muscles of the abdomino-pelvic cavity. The potential for muscle substitution strategies reinforces the need for close attention to specificity when prescribing PFM exercise programs.     

Vaginismus, a Component of a General Defensive Reaction. An Investigation of Pelvic Floor Muscle Activity during Exposure to Emotion-Inducing Film Excerpts in Women with and without Vaginismus

This study investigates the mechanism underlying vaginismus, which may be part of a general defense mechanism. Exposure to a threatening situation will evoke an increase in muscle activity. This muscle reaction will not be restricted to the pelvic floor but will also occur in postural muscles, such as in the trapezius region. Women with and without vaginismus were exposed to four stimuli: excerpts from threatening, erotic, neutral and sexual-threatening films. Subjects were 45 physician- or self-referred patients with vaginismus and 32 controls with no sexual or pelvic floor complaints. The activity of the pelvic floor muscles and of the muscles in the trapezius region was recorded with surface electrodes. There were no differences between women with and without vaginistic reactions. EMG measurement of both the pelvic floor muscles and the trapezius muscle showed an increase in muscle activity during the threatening and sexual-threatening excerpts in women with and without vaginismus. This increase of involuntary pelvic floor muscle activity is part of a general defense mechanism that occurs during exposure to threatening situations. This reaction is not restricted to a situation with a sexual content. The results of this study shed new light on the concept of vaginismus as a primarily sexual dysfunction.     

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.     

Voluntary Control Over Pelvic Floor Muscles in Women With and Without Vaginistic Reactions

The ability to voluntarily contract and relax the pelvic floor muscles may differentiate between women with and without vaginistic reactions. This was investigated using intravaginal surface electromyographic (EMG) recordings of the pelvic floor muscles and EMG measurements of the surrounding muscle groups, during muscle exercises. Sixty-seven physician- or self-referred women with vaginismus and 43 control subjects participated. They performed six short flick contractions and three 10-second holding contractions. No difference in baseline was found between groups, indicating a comparable level of relaxation. There was no difference between groups in the performance of the exercises. As the women with vaginistic reactions do not have less voluntary control, treatment should not be based solely on an increase in control.     

Pelvic floor muscle exercise for the treatment of female stress urinary incontinence: II. Validity of vaginal pressure measurements of pelvic floor muscle strength and the necessity of supplementary methods for control of correct contraction

The present investigation comprises three methodological studies concerning vaginal pressure measurements of pelvic floor muscle (PFM) strength. Vaginal pressure was measured by a balloon (6.7 ± 1.7 cm) connected by a catheter to a pressure transducer. The balloon was placed with the middle of the balloon 3.5 cm inside the introitus vagina. In fourty-seven women, mean age 44.9 years (24–64), observation of movement of the vaginal catheter during PFM contraction verified 7 inconclusive results from perineovaginal palpation and was the most valid way to distinguish between correct and incorrect PFM contraction. Vaginal pressure rise was obtained regardless of correct or incorrect PFM contraction, showing that vaginal pressure is not specific for PFM contraction. However, as the action of the PFM is elevation, a simultaneous inward movement of the vaginal catheter is present only during correct PFM contraction. Degree of influence of various muscle groups on vaginal pressure was investigated in 14 women using two different balloons, one having a silicone reinforcement of the tip. It was found that the median contraction value of muscles other than the PFM did not exceed contraction of PFM alone. No significant difference was observed using the two types of balloons. In three physical therapists EMG activity of the lower m. rectus abdominis was recorded during maximal PFM contractions. A rise in EMG activity always occurred during maximal contractions even if the women actively tried to relax the abdominal muscles. It is concluded that vaginal pressure measurement of PFM strength is valid with simultaneous observation of inward movement of the balloon catheter. Vaginal pressure rise due to simultaneous contraction of other muscles is probably not larger than pressure rise due to intended PFM contraction. Reinforced balloon tip will not change pressure recording, and rise in EMG activity of lower abdominal muscles seems unavoidable during maximal PFM contraction.     

Pelvic Floor and Abdominal Muscle Interaction: EMG Activity and Intra-abdominal Pressure

Pelvic floor muscle exercises prescribed for the treatment of incontinence commonly emphasize concurrent relaxation of the abdominal muscles. The purpose of this study was to investigate the interaction between individual muscles of the abdominal wall and the pelvic floor using surface and intramuscular electromyography, and the effect of their action on intra-abdominal pressure. Four subjects were tested in the supine and standing positions. The results indicated that the transversus abdominis (TA) and the obliquus internus (OI) were recruited during all pelvic floor muscle contractions. It was not possible for these subjects to contract the pelvic floor effectively while maintaining relaxation of the deep abdominal muscles. A mean intra-abdominal pressure rise of 10 mmHg (supine) was recorded during a maximum pelvic floor muscle contraction. These results suggest that advice to keep the abdominal wall relaxed when performing pelvic floor exercises is inappropriate and may adversely affect the performance of such exercises.     

The Urethral Pressure Profile and Ultrasound Imaging of the Lower Urinary Tract

In a prospective study 105 patients with symptoms of stress incontinence underwent videourodynamic testing, including resting urethral pressure profilometry and translabial ultrasound. The urethral pressure profile (UPP) included maximum urethral closure pressure (MUCP), functional length (FL) and area under the curve (AUC). Ultrasound parameters included urethral thickness, urethral rotation and bladder neck descent, as well as funneling/opening of the internal urethral meatus on Valsalva maneuver. Levator contraction strength was assessed measuring the cranioventral displacement of the internal meatus. Negative correlations between UPP data and age, parity and previous surgery were observed which were consistent with literature data. There was a positive correlation between the urethral AP diameter on ultrasound and the MUCP, which agrees with reports showing reduced sphincter thickness or volume in stress-incontinent women. Hypermobility on ultrasound did not correlate with UPP data. However, a lower MUCP correlated with extensive opening of the bladder neck. Finally, there was a trend towards poorer pelvic floor function with lower MUCP measurements.     

Relationship between abdominal and pelvic floor muscle activation and intravaginal pressure during pelvic floor muscle contractions in healthy continent women

AIM: Activation of the abdominal muscles might contribute to the generation of a strong pelvic floor muscle contraction, and consequently may contribute to the continence mechanism in women. The purpose of this study was to determine the abdominal muscle activation levels and the patterns of muscle activity associated with voluntary pelvic floor muscle (PFM) contractions in urinary continent women. METHODS: Fifteen healthy continent women participated. They performed three maximal contractions of each of the four abdominal muscles and of their PFMs while in supine. Abdominal and PFM activity was recorded using electromyography (EMG), and intravaginal pressure was recorded using a custom modified Femiscan probe. RESULTS: During voluntary maximal PFM contractions, rectus abdominus was activated to 9.61 (+/-7.42)% maximal voluntary electrical activity (MVE), transversus abdominus was activated to 224.30(+/-47.4)% MVE, the external obliques were activated to 18.72(+/-13.33)% MVE, and the internal obliques were activated to 81.47(+/-63.57)% MVE. A clear pattern of activation emerged, whereby the transversus abdominus, internal oblique, and rectus abdominus muscles worked with the PFM in the initial generation of maximal intravaginal pressure. PFM activity predominated in the initial rise in lower vaginal pressure, with later increases in pressure (up to 70% maximum pressure) being associated with the combined activation of the PFM, rectus abdominus, internal obliques, and transverses abdominus. These abdominal muscles were the primary source of intravaginal pressure increases in the latter 30% of the task, whereas there was little increase in PFM activation from this point on. The external oblique muscles showed no clear pattern of activity, but worked at approximately 20% MVE throughout the PFM contractions, suggesting that their role may be predominantly in postural setting prior to the initiation of intravaginal pressure increases. CONCLUSIONS: Defined patterns of abdominal muscle activity were found in response to voluntary PFM contractions in healthy continent women.     

Effect of abdominal and pelvic floor tasks on muscle activity, abdominal pressure and bladder neck

Introduction and hypothesis  

Although the bladder neck is elevated during a pelvic floor muscle (PFM) contraction, it descends during straining. This study aimed to investigate the relationship between bladder neck displacement, electromyography (EMG) activity of the pelvic floor and abdominal muscles and intra-abdominal pressure (IAP) during different pelvic floor and abdominal contractions.     

Initial experience with a new method for the dynamic assessment of pelvic floor function in women: the Kolpexin Pull Test

The aim of this study was to evaluate a newly developed, simple test for assessing pelvic floor muscular function in women. Pelvic floor strength in women with symptomatic pelvic floor dysfunction was evaluated with a newly developed assessment tool, the Kolpexin Pull Test, and compared to a clinically validated digital pelvic floor strength assessment scale (DPA). A 36-mm Kolpexin sphere was inserted into the vagina above the levator plate and connected to a digital tensiometer/force gauge. The force required to remove the sphere was recorded for three resting trials and three maximum pelvic floor contractions. Results of the DPA and Kolpexin Pull Test were analyzed using ANOVAs of contrast variables, intraclass correlations, and regression analyses. Twenty-one women participated in the study. Age range was 36–85 years, parity range was 2–5. All six trials required less than 5 min to perform in each patient. Intraperson maximum contraction data were correlated at 0.96 (95% CI: 0.91, 0.98), and were greater at higher DPA scores (p=0.016). There were positive correlations between the maximum contraction and DPA data (adjusted R²=0.52; p <0.001), and the maximum contraction minus resting vs DPA data (adjusted R²=0.54; p< 0.001). The Kolpexin Pull Test is reproducible, rapid, and correlates with digital clinical assessment of pelvic floor strength during maximal contractions.Abbreviations DPA Digital pelvic assessment - MC Maximum pelvic floor contraction - RP Relaxed pelvic floor Editorial Comment: This paper is an interesting pilot study of a new technique to measure pelvic muscle strength. Several other techniques have already been described. As the authors have stated, all methods have flaws, including the relatively easy and reproducible digital pelvic assessment (DPA). The Kolpexin sphere offers the hope of more objective testing than the DPA, overcomes the contribution of Valsalva to the pressure perineometry readings, and is easier to perform than ultrasound or EMG. The authors did not fully convince us of the objectivity of the measurements, as the study was not blinded. Also, we do not know whether the size of the sphere altered the readings in women in different heights and/or weights. If, on further testing, this technique is shown to have inter- as well as intraexaminer reproducibility, it may contribute to the evaluation of patients for management as well as for research.     

Assessment of pelvic floor muscle contraction in stress urinary incontinent women: comparison between transabdominal ultrasound and perineometry

Introduction and hypothesis  

Transabdominal (TA) ultrasound and perineometry have been currently used to assess lifting aspect and squeezing action of pelvic floor muscles (PFM) function, respectively, in women with stress urinary incontinence (SUI). However, no study has directly compared these measurements. The purpose of this study was to investigate the reliability and correlation between perineometry and TA ultrasound as measurements of different aspect of PFM function.     

Women with SUI demonstrate motor control differences during voluntary pelvic floor muscle contractions

Introduction and hypothesis  To compare maximum abdominal and pelvic floor muscle (PFM) electromyographic (EMG) and intravaginal pressure (IVP) amplitudes and muscle activation patterns during voluntary PFM contractions between women with and without stress urinary incontinence (SUI). Methods  Twenty-eight continent women and 44 women with SUI performed single and repeated PFM contractions in supine. Surface EMG data were recorded simultaneously with IVP. Maximum EMG and IVP amplitudes and ensemble average IVP versus EMG curves were determined from the single contractions. Muscle activation timing was determined with cross-correlation functions from the repeated contractions. Results  The continent group produced higher PFM EMG amplitudes than the SUI group; there were no between group differences in IVP. The women with SUI delayed activating rectus abdominus. The IVP versus EMG curves’ shapes were similar between the groups, however the SUI group had higher abdominal muscle y-intercepts than the continent women. Conclusions  These findings suggest that women with SUI demonstrate altered motor control strategies during voluntary PFM contractions.     

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.     

Levator hiatus dimensions and pelvic floor function in women with and without major defects of the pubovisceral muscle

Introduction and hypothesis

The aim of present study was to compare pelvic floor morphology and function in women with and without major defects of the pubovisceral muscle.

Methods

One hundred fifty-seven women with pelvic organ prolapse participated in this cross-sectional study. Participants answered a symptom questionnaire and underwent clinical and three- and four-dimensional transperineal ultrasound examination. Pelvic floor muscle maximum voluntary contraction (MVC), endurance, and resting vaginal pressure were registered with a vaginal balloon catheter. Offline analyses were performed for the presence of major pubovisceral muscle defects (PVMD) and hiatal dimensions.

Results

The levator hiatus dimensions at rest and contraction were significantly larger in women with than without major PVMD. Mean differences in levator hiatus area between women with and without major PVMD were: rest 1.9?cm² 95% confidence intervals (CI) 0.21–3.7, P?=?0.028 and contraction 2.75?cm² 95% CI 1.0–4.5, P =0.002; and Valsalva maneuver mean difference was 0.82?cm² 95% CI 2.18–3.83, P?=?0.543. Women with major PVMD had lower MVC and endurance measurements as compared with women without major PVMD, but the differences were not statistically significant.

Conclusions

Women with major pubovisceral muscle defects have larger hiatal dimensions at rest and at contraction than women without PVMD. We were unable to prove the corresponding relationship for hiatal dimensions on Valsalva.     

Evaluation of pelvic floor muscle function in a random group of adult women in Austria

Despite an increasing clinical interest in female pelvic floor function, there is a lack of data with respect to the knowledge of average adult women about the physiological role of the pelvic floor and their ability to contract pelvic floor muscles (PFM) voluntarily. It was the aim of our study to evaluate the percentage of PFM dysfunction in adult women and the impact of risk factors, such as age, body mass index (BMI), number of children delivered, and the influence of previous PFM training. A total of 343 Austrian adult women (mean age, 41.2 ± 14.6 years; range, 18–79 years), selected at random, were examined to test their ability to contract the PFM. The examination was carried out by three independent gynecologists during the course of a routine gynecological visit. The ability to contract the PFM voluntarily or involuntarily was assessed by digital intravaginal palpation with the patients in a supine position. The muscle strength was graded according to the Modified Oxford Grading Scale by Laycock. A high percentage (44.9%) of the women was not able to voluntarily perform a normal PFM contraction. In only 26.5%, an involuntary contraction of the pelvic floor was present before an increase in intra-abdominal pressure. The inability to contract the PFM did not correlate with women’s age but revealed a weak relationship with the number of childbirths and the patient’s BMI. A significant correlation was found between the Oxford Grading Scale rating and the patient’s report about previous PFM training.     

Conservative Treatment of Stress Urinary Incontinence in Women: Who will Benefit?

The aim of the study was to find out which factors can predict the outcome of conservative treatment of urinary stress incontinence in women. One hundred and four women with stress urinary incontinence were evaluated by recall, and by clinical and urodynamic investigation and were given pelvic floor muscle exercises with or without the use of biphasic low-frequency electrostimulation and visual biofeedback. Two groups could be distinguished. The first consisted of 37 patients in whom conservative therapy proved successful; the second consisted of 67 patients in whom incontinence continued. The study investigated whether there was a significant difference in patients’ characteristics between the two groups. The number of conservative treatment sessions was not different between the two groups. The presence of a high body mass index, previous pelvic surgery, strong levator muscles and urethral hypermobility appeared to be poor prognostic features. More research is required to evaluate which patients can benefit from conservative treatment and which criteria can predict the outcome of pelvic floor physiotherapy in women with stress incontinence. This way, patients selection is possible and excessive costs can be saved.     

Pelvic muscle activity in nulliparous volunteers

The aim of this study was to describe normal characteristics of spontaneous and voluntary pelvic muscle function in nulliparous healthy continent women and to assess the reaction of the pelvic floor to stress and fatigue. Ten nulliparous volunteers were recruited. Pelvic muscle strength was evaluated by palpation and perineal ultrasound. Kinesiological EMG and perineal ultrasound were performed to test for possible fatigue and to assess bladder neck mobility during coughing with a pre-contraction of the pelvic floor muscles. Bladder neck mobility did not increase after attempts to fatigue the pelvic floor muscles. Bladder neck descent was significantly less when the women were instructed to contract the pelvic floor muscles before coughing. The contraction of the pelvic floor muscles stabilizes the vesical neck in nulliparous women.     

Pelvic floor electromyography in men with chronic pelvic pain syndrome: a case-control study

AIMS: The objectives of this study were (1) to identify differences between men with chronic pelvic pain syndrome (CPPS), compared with pain-free men, in surface electromyography/biofeedback (sEMG/BFB) readings of pelvic floor muscles and (2) to determine which pelvic floor muscle sEMG readings may have differential diagnostic and treatment selection value by accurately predicting group membership, CPPS versus normal. METHODS: Twenty-one men with CPPS and 21 healthy men without pelvic pain underwent a standardized sEMG examination by a licensed physical therapist. RESULTS: On group difference measures men with CPPS showed significantly greater sEMG instability in preliminary resting baseline. Three sEMG measures reliably categorized CPPS versus normals with CPPS showing greater preliminary resting baseline hypertonicity and instability with lowered voluntary endurance contraction amplitude. CONCLUSIONS: CPPS patients manifest pelvic floor muscle instability compared to normals. Prebaseline resting hypertonicity and instability along with endurance contraction weakness reliably predicts subject membership in the CPPS vs. normal group. Pelvic floor muscle sEMG may be a valuable screening tool to identify patients with CPPS who may benefit from therapies aimed at correcting pelvic floor muscle dysfunction.