Pelvic Floor Muscle Activity Research Articles

The effect of aging on the electromyographic activity of pelvic floor muscles: A comparative study among stress incontinent patients and asymptomatic women

Objectives: Pelvic floor muscle training (PFMT) is commonly used in combination with biofeedback devices for stress urinary incontinence. A new electromyography (EMG)-based home-use device for PFMT is tested for healthy and stress incontinent patients. Subjects and methods: Altogether 31 women with genuine stress incontinence (GSI) and 35 controls without urinary symptoms were measured with a vaginal surface EMG probe. EMG activity during three rapid contractions (5 s) in supine and standing positions were observed. Results: Mean values of three rapid contractions were 17.0 μV (range 6.5–59.0, S.D. 10.5) in the supine position and 12.9 μV (range 5.0–33.0, S.D. 5.9) in the standing position among incontinent patients and 19.5 μV (range 9.0–43.5, S.D. 8.4) and 18.2 μV (range 8.0–43.5, S.D. 8.7) among the controls, respectively. A significant difference ( P=0.006) was found in the mean values of three rapid contractions in the standing position between GSI patients and asymptomatic women. In regression analysis, EMG values were dependent on age ( P=0.004 in the supine, P=0.009 in the standing) in both groups, but not on parity, body mass index (BMI) or episiotomies. Conclusions: In the study groups, the EMG activity of pelvic floor muscles (PFMs) decreased during aging. Although the tested surface EMG device showed a tendency that incontinent patients have lower PFM activities especially in the standing position, the value of surface EMG method as a diagnostic tool is not well established. However, the tested EMG-based device for PFMT will be helpful as guidance for incontinent patients.

Increase in pelvic floor muscle activity after 12 weeks’ training: a randomized prospective pilot study

Objectives To compare electromyography-assisted biofeedback training to pelvic floor muscle training (PFMT) alone in patients with female stress urinary incontinence. Methods A prospective randomized pilot study was conducted between March 1998 and February 2000 at the university hospital for outpatient care. Participants were women with urodynamically tested stress incontinence aged 31 to 69 years without previous incontinence operations, 30 volunteers altogether. The biofeedback group received an electromyography-guided biofeedback device for home training and the PFMT-alone group trained without any device at home. All patients were advised to practice for 20 minutes per day five times a week for 12 weeks. Results According to the data analysis, muscle forces increased significantly in both supine ( P <0.001) and standing ( P <0.001) positions. In the supine position, the increase was significantly higher in the biofeedback group ( P = 0.024). The results showed close to a significant decrease in the leakage index in the biofeedback group ( P = 0.068), but in the PFMT-alone group, no change occurred. With respect to the pad test, the decrease was significant, but it was the same for both groups ( P = 0.907). Conclusions The findings of this study show that pelvic floor muscle activity is increased and the amount of leaked urine is decreased after 3 months of PFMT. These preliminary results show a significant improvement compared with the PFMT-alone group in PFMT outcome measures in patients using electromyography-assisted biofeedback training.

The Pelvic Floor: A clinical model for function and rehabilitation

Summary The pelvic floor forms the inferior boundary of the abdomino-pelvic cavity. The co-ordinated action of the muscles which surround this cavity generates intra-abdominal pressure, with the pelvic floor muscles acting before the pressure rise to maintain organ support and urinary and faecal continence. When the pelvic floor muscles lose their automatic co-ordinated function, it is the timing of muscle recruitment, as well as the endurance and strength, which is deficient. This paper presents a theory on how automatic pelvic floor muscle activity operates in healthy women, discusses how it is lost, suggests a non-invasive way of testing it, and proposes a programme to restore the automatic recruitment timing of the muscles, as well as their endurance and strength, to optimise rehabilitation outcomes.

Contraction of the pelvic floor muscles during abdominal maneuvers

Sapsford RR, Hodges PW. Contraction of the pelvic floor muscles during abdominal maneuvers. Arch Phys Med Rehabil 2001;82:1081-8. Objective: To determine whether voluntary abdominal muscle contraction is associated with pelvic floor muscle activity. Design: Pelvic floor muscle activity was recorded during contractions of the abdominal muscles at 3 different intensities in supine and standing positions. Setting: Research laboratory. Participants: Six women and 1 man with no histories of lower back pain. Intervention: Not applicable. Main Outcome Measures: Electromyographic activity of the pelvic floor muscles was recorded with surface electrodes inserted into the anus and vagina. These recordings were corroborated by measurements of anal and vaginal pressures. Gastric pressure was recorded in 2 subjects. Results: Pelvic floor muscle electromyography increased with contraction of the abdominal muscles. With strong abdominal contraction, pelvic floor muscle activity did not differ from that recorded during a maximal pelvic floor muscle effort. The pressure recordings confirmed these data. The increase in pressure recorded in the anus and vagina preceded the pressure in the abdomen. Conclusions: In healthy subjects, voluntary activity in the abdominal muscles results in increased pelvic floor muscle activity. The increase in pelvic floor pressure before the increase in the abdomen pressure indicates that this response is preprogrammed. Dysfunction of the pelvic floor muscles can result in urinary and fecal incontinence. Abdominal muscle training to rehabilitate those muscles may be useful in treating these conditions. © 2001 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Digital Vaginal Assessment: An inter-tester reliability study

Summary Background and Purpose A variety of methods may be employed to assess pelvic floor muscle activity, the most widely used being digital vaginal assessment. However, this is a subjective form of assessment and consequently there are issues concerning reliability when two or more clinicians are involved in assessment before and after treatment of patients with urinary incontinence. This article presents the results of a study assessing inter-tester reliability between four clinicians on three different sites. Methods Thirty patients (ten for each clinician from three sites) were assessed by four clinicians. One clinician from each of the three sites was compared to a fourth. Each patient was assessed twice (once by clinician 1, 2 or 3 and once by clinician 4). All four clinicians adhered to the same written protocol and were prevented from conferring until the end of the investigation. Results For clinicians 1 and 3 there were few discrepancies between their scores and those of clinician 4. However, initially there were considerable differences in assessment techniques between clinicians 2 and 4. After appropriate training the disparity between these two clinicians was considerably reduced. Conclusions Inter-tester reliability should not be assumed between clinicians and should be established when two or more clinicians are involved in pre-and post-treatment assessment. If disparity does occur between assessors the difference in assessment technique may be overcome with appropriate training.

The relationship between involuntary pelvic floor muscle activity, muscle awareness and experienced threat in women with and without vaginismus

This study assessed the relationship between involuntary pelvic floor muscle activity, muscle awareness and experienced threat in women with and without vaginismus. Information about this relationship may help understand the mechanism of vaginismus. Twenty-two women with vaginismus and seven control women participated in the study. Women were exposed to four emotion-inducing film excerpts. Vaginal electromyography was recorded. Experienced threat was continuously monitored with the use of a lever. Women responded with increased pelvic floor muscle activity to the threatening and sexually-threatening film excerpt. No changes occurred during the neutral and erotic excerpt. The subjective experienced threat as indicated with the lever showed the same response pattern. However, awareness of changes in muscle activity showed a slightly different pattern. Individual data were inspected. In general, agreement was found between recorded changes in muscle activity and experienced threat. The results of the erotic excerpt showed that awareness of changes in muscle activity is not only determined by information from the pelvic floor muscles, but also by other factors like situational information and the expectations of the women. The data support the idea of a general defense reaction as a mechanism of involuntary pelvic floor muscle activity.

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.

Dysfunctional voiding in women: which muscles are responsible?

To analyse the striated external urethral sphincter (EUS) and pelvic floor muscles using two different electromyography (EMG) techniques in women with dysfunctional voiding and/or urinary retention. Fifteen women (mean age 38.2 years, range 18-61) with dysfunctional voiding and/or unexplained voiding dysfunction associated with urinary retention were examined neurologically and urologically; urodynamics and kinesiological EMG of the bilateral pubococcygeal and external urethral striated sphincter muscles were obtained. In an additional neurophysiological session, concentric-needle EMG of the external urethral sphincter was performed. Kinesiological EMG recordings revealed inappropriate pelvic floor muscle activation during voiding in 11 and EUS activation in four women. Concentric needle EMG of the EUS revealed complex repetitive discharges in the four women with inappropriate urethral sphincter activation recorded by kinesiological EMG during voiding. Biofeedback training led to improvement in women with inappropriate pubococcygeal activation but not in those with urethral sphincter complex repetitive discharges. Urodynamic examinations in combination with kinesiological EMG examination of the pubococcygeal and external urethral sphincter muscles revealed two groups of women with dysfunctional voiding. Further diagnostic evaluation of such patients with concentric-needle EMG is mandatory. The differentiation of the two groups is therapeutically relevant.

Can simultaneous perineal sonography and urethrocystometry help explain urethral pressure variations?

To correlate urodynamic with perineal sonographic findings in pressure variations. In 15 women presenting with urethral pressure variations a urodynamic evaluation with water filling cystometry, urethral pressure at rest and during coughing and uroflowmetry were performed. During water filling cystometry, there were simultaneous perineal video-sonography and urethrocystometry. Video ultrasound images and urodynamic curves were simultaneously monitored on a computer screen. Simultaneous ultrasound and urodynamic evaluation in the 15 patients revealed movements in two areas leading to urethral pressure variations: activity of the pelvic floor muscles and of the urethral sphincter muscles. For the pelvic floor, we found either slow or fast contractions with, respectively, slow (15-30 cm H2O for 3-10 sec) or fast (30-130 cm H2O for 1-3 sec) urethral pressure changes. Urethral sphincter contractions were always fast, resulting in fast pressure changes of 30-170 cm H2O for 1-3 sec. Evaluation of simultaneous perineal sonography and urethrocystometry shows the association of urethral pressure variations and muscle activity. Urethral pressure variations are caused by the activity of urethral sphincter or pelvic floor muscles. With ultrasound the activity of the urethral sphincter muscle can directly be seen whereas pelvic floor muscle activity is indirectly visible. Pelvic floor muscle contractions are either fast or slow, whereas the urethral sphincter muscle contractions are always fast contractions.

Can simultaneous perineal sonography and urethrocystometry help explain urethral pressure variations?

Objective: To correlate urodynamic with perineal sonographic findings in pressure variations. Patients and methods: In 15 women presenting with urethral pressure variations a urodynamic evaluation with water filling cystometry, urethral pressure at rest and during coughing and uroflowmetry were performed. During water filling cystometry, there were simultaneous perineal video-sonography and urethrocystometry. Video ultrasound images and urodynamic curves were simultaneously monitored on a computer screen. Results: Simultaneous ultrasound and urodynamic evaluation in the 15 patients revealed movements in two areas leading to urethral pressure variations: activity of the pelvic floor muscles and of the urethral sphincter muscles. For the pelvic floor, we found either slow or fast contractions with, respectively, slow (15–30 cm H2O for 3–10 sec) or fast (30–130 cm H2O for 1–3 sec) urethral pressure changes. Urethral sphincter contractions were always fast, resulting in fast pressure changes of 30–170 cm H2O for 1–3 sec. Conclusion: Evaluation of simultaneous perineal sonography and urethrocystometry shows the association of urethral pressure variations and muscle activity. Urethral pressure variations are caused by the activity of urethral sphincter or pelvic floor muscles. With ultrasound the activity of the urethral sphincter muscle can directly be seen whereas pelvic floor muscle activity is indirectly visible. Pelvic floor muscle contractions are either fast or slow, whereas the urethral sphincter muscle contractions are always fast contractions.

Dynamic assessment of pelvic floor function in women using the intravaginal device test.

The aim of the study was to assess pelvic floor function and dysfunction using intravaginal devices (IVD test). One hundred and eighty-five patients were evaluated, 65 (35.1%) in the control group without genital prolapse and 120 (64.9%) in the study group, with prolapse. Anatomic changes were evaluated on a scale described by Halban, and functional classification based on palpation of the muscles of the pelvic floor during contraction. Additionally, weighted vaginal devices were used to assess pelvic floor function. Statistic analysis was performed with the Spearman-Pearson correlation coefficient, the chi2 test and the response/operator characteristic curve. There was an acceptable correlation between the IVD test and the functional classification of 0.75. Using this classification, the IVD test showed 86.58% sensitivity, 75.72% specificity, and had a positive predictive value of 73.95% and a negative predictive value of 87.64%. Significant differences between pelvic floor muscle activity in those patients with and without genital prolapse were observed (chi2 = 58.28, P=<0.005). It was concluded that pelvic floor assessment can be done through the evaluation of active muscle strength or pelvic floor integrity using the functional classification and the IVD test.

Linearisation of a urinary flow transducer

URODYNAMICS IS a subdiscipline of urology concerned with the function of the lower urinary tract on the basis of information in physical signals such as the urinary flow rate, pressures measured in the bladder and the rectum (or abdominal cavity), as well as voltage variations reflecting pelvic floor muscle activity (EMG) (GRIFFtTHS, 1980). This work focuses on the measurement of the urinary flow rate. tn urodynamics, at least two different types of flow meters are in use. The first type simply measures the weight of the voided volume as a function of time. Differentiation of this signal provides an assessment of the urinary flow rate (COOLSAET and VAN DUYL, t981; ROLLEMA, 198t). The essential part of the second type of flow meter is a rotating disk. This disk is kept at a constant angular velocity by means of a feedback control system. Urine that hits the disk is accelerated to the circumferential speed of the disk. The extra energy necessary for this acceleration is proportional to the mass of the urine that 'flows through' the device per unit of time. The rotating disk technique has important advantages over the other type of flow meter (TAMMEN, 1971a, b; ROWAN et al., 1977). As rotathag disk flow transducers have a nonlinear transfer fianction, the output signal should be linearised. In commercial umdynamic measurement systems, such a linearisation is built in by the manufacturer. These complete measurement systems are very expensive and not very atwactive to research institutions; real-time output signals are usually not available and the possibilities for signal processing are limited. We have therefore decided to develop a urodynamic measurement system using a personal computer, an analogue digital convertor and a flow transducer. This work describes a simple linearisation procedure for this type of flow transducer. The method has been tested on six flow trmasducers.

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.

Surface electromyography of pelvic floor muscles in healthy children. Methodological study.

Pelvic floor muscle activity was recorded in ten healthy children, aged six to ten years, by using surface electromyography and a polygraph writer. The electromyograms were recorded simultaneously from four electrode pairs on the perineum and three electrode pairs on adjacent muscle groups, i.e. hip and abdominis muscles. The children performed ten different manoeuvres. Necessary prerequisites for this investigatory method include good electrode application, adequate instruction of the child and the child's adjustment to the method. Using the described procedure, it was possible to record pelvic floor muscle activity without any appreciably detectable electrical influence from adjacent muscles. The method sometimes allows selective recording of electromyographic activity between the ventral urogenital and the dorsal anal regions. Therefore both anal and urethral electrode pairs should be used to achieve functional information about the pelvic floor muscles. The envisaged method should be useful as a tool for assessment of pelvic floor muscle exercises in children with voiding disorders.

Physiotherapeutic aspects of urine incontinence.

Women suffering from urinary incontinence often lose proper control of their abdominal and pelvic floor muscles. A comprehensive program for differential diagnosis and therapy was therefore devised and tested. Briefing of patients on functional anatomy, application of a pulsating electric current, and exercises in respiration and mobility for the activation of pelvic floor muscles are major therapy elements. Groups of up to 30 start off by exchanging experiences of complaints, followed by exercises coached by an experienced physiotherapist. Beginners and advanced patients are grouped together and separated only for electrotherapy. Some 4-6 weeks are required for treatment (four sessions weekly and 2 hours of attendance daily). Continence was restored by such treatment in 23 of 82 patients (28%), and 38 (46%) improved greatly. Best results were obtained from I. - II. cases. Integration of physiotherapy with multistep therapy for urinary incontinence is described.