Does the presence of a vaginal probe alter pelvic floor muscle activation in young, continent women?

Techniques for Registration of Myoelectric Activity of Women's Pelvic Floor Muscles: A Scoping Review

INTRODUCTION AND HYPOTHESIS

Surface electromyography is commonly applied to measure the electrophysiological activity of the neuromuscular system. However, there is no consensus regarding the best protocol to assess pelvic floor muscles.

METHODS

A scoping literature review was carried out in six databases, using MeSH descriptors. It included studies with electromyographic assessment in adult women presenting or not with pelvic floor dysfunction. The results were presented in categories to contribute to the development of a protocol considering the most used parameters for non-invasive assessment of myoelectric activity of pelvic floor muscles.

RESULTS

A total of 1,074 articles were identified, and 146 studies were selected for analysis. The intravaginal probe was used in 80.8% of the studies, the bipolar sensor with metallic plates placed on both sides of the vagina was the most frequent (71.3%), with a reference electrode positioned on the anterior superior iliac spine (33.5%). The supine position with hip and knee flexed (45.2%) was the most frequent position used. Of the studies, 44.5% normalized the data by maximum voluntary contraction (MVC) whereas 44.5% performed an average of 3 MVCs.

CONCLUSIONS

The most frequently used protocol for the pelvic floor is the bipolar intracavitary probe with metal plates positioned at 3-9 o'clock and introduced distally to the vaginal introitus with the volunteer in the supine position and the hip and knee flexed with the reference placed on the anterior-superior iliac spine.

Between-sexes differences in lumbopelvic muscle mechanical properties of non-climacteric adults: a cross-sectional design

The lumbopelvic muscle mechanical properties (MMPs) are clinically relevant, but their dependence on sex remains unknown. Therefore, this study aimed to identify if lumbopelvic MMPs depend on the sex in a young adult population. Thirty-five healthy nulliparous women and 35 healthy men were analyzed (age range: 18-50). Lumbopelvic MMPs, that is, tone, stiffness, elasticity, relaxation and creep, assessed with MyotonPRO®, and pelvic floor (PF) health questionnaires were compared between-sexes. Intra-group correlations between sociodemographic and clinical data, and MMPs were also determined. The MMPs of PF were different between healthy non-climacteric adults of both sexes, with women showing higher values of tone and stiffness and lower values of elasticity and viscoelastic properties than men (in all cases, p < 0.03). At lumbar level, tone and stiffness were higher for men at both sides (in all cases, p < 0.04), and relaxation was lower at left side (p = 0.02). The MMPs showed few correlations with sociodemographic data within women. However, within males, there were positive correlations for PF stiffness and viscoelastic parameters with age, BMI and function (0.334 < r < 0.591) and, at lumbar level, negative correlations for tone and stiffness ( - 0.385 < r < -0.590) and positive correlations for viscoelastic properties (0.564 < r < 0.719), with BMI. This indicated that between-sexes differences of lumbopelvic MMPs depend on the specific location of assessment in healthy non-obese young individuals. Women show higher tone and stiffness and lower elasticity and viscoelasticity than men, at PF level.

Evaluation of Pelvic Floor Muscles in Pregnancy and Postpartum With Non-Invasive Magnetomyography

Objective: To record and characterize features of levator ani muscles (LAM) activity in pregnancy and postpartum using non-invasive and novel Magnetomyography (MMG) technique with amplitude and spectral parameters. Methods: Nulliparous women with uncomplicated pregnancies participated in the MMG data collection during rest and voluntary LAM contractions (Kegels) with modulated intensity in third trimester and approximately 2 months postpartum (PP). Simultaneous surface electromyography was recorded to document the recruitment of accessory muscles. Moderate strength Kegel (MK) MMG trials were analyzed. Amplitude and spectral parameters including root-mean square (RMS) amplitude, power spectrum density (PSD) and normalized PSD (rPSD) in three frequency bands (low, middle, high) were computed on MK epochs. Statistical comparisons between pregnancy and postpartum were calculated. Results: MMG recordings were measured from 10 pregnant women. Results showed decreased RMS and power between third trimester and postpartum, trending towards significance. rPSD values in the low frequency band decreased significantly (p = 0.028) from third trimester to postpartum, while significant increase was observed in the middle frequency band (p = 0.018). Conclusions: This study shows that MMG as non-invasive tool has the ability to detect and characterize changes of LAM activity with amplitude and spectral parameters during pregnancy and postpartum.

Postoperative Physiotherapy in Women Undergoing Pelvic Floor Reconstructive Surgery: A Randomized Controlled Clinical Trial

Purpose: Postoperative physiotherapy in conjunction with pelvic organ prolapse (POP) surgery is still under-investigated and controversial. In this randomized controlled trial, pelvic floor muscle training (PFMT) and abdominal training were compared with a control condition (standard in-hospital treatment). Method: Eighty-one women were randomized to one of three groups. The Prolapse Quality of Life questionnaire, two-dimensional ultrasound, Pelvic Organ Prolapse Quantification System scale, the PERFECT (power, endurance, repetitions, fast contractions, every contraction timed) scheme, electromyography, Sahrmann scale, and pressure biofeedback unit (PBU) were used to measure quality of life (QOL), POP, and pelvic floor and abdominal muscle function. A mixed-model analysis of variance and the Kruskal-Wallis test was used for analysis. Results: Beneficial effects (p < 0.05) were found for the PFMT group - increased power, number of fast contractions, amount of movement, endurance, and Sahrmann and PBU measures - compared with the control group. Abdominal training led to a significant (p < 0.05) increase in bulging and discomfort, number of pelvic floor muscle contractions, and Sahrmann and PBU measures compared with the control condition; both groups showed significantly increased urinary frequency (p < 0.05). Conclusions: Postoperative physiotherapy did not have a beneficial effect on QOL or POP symptoms. PFMT and abdominal training had beneficial effects on pelvic floor muscle function and abdominal muscle measures. Additional abdominal training led to increased symptoms.

The Prognostic Value of the Surface Electromyographic Assessment of Pelvic Floor Muscles in Women with Stress Urinary Incontinence

Background: The use of surface electromyography (sEMG) measurements to evaluate the bioelectrical activity of the pelvic floor muscle (PFM) during therapeutic intervention is now well established. This study investigates the diagnostic possibilities of sEMG in women with stress urinary incontinence (SUI). The aim of this study was to carry out objective assessments of the bioelectrical activity of the PFM in women after menopause and determine the prognostic value of sEMG for assessing the PFM in patients with SUI. Methods: This was a prospective, observational study that evaluated the bioelectrical activity of the PFM in postmenopausal women with or without SUI (SUI group, n = 89 vs. non-SUI group, n = 62). The study was carried out between January 2013 and December 2018 at the Clinic of Urology (Wroclaw, Poland). The protocol for all sEMG measurements of PFM activity consisted of following elements: “baseline”, “quick flicks”, “contractions”, “static hold”, and “rest tone”; we then compared these results between groups. To determine the optimal cutoff level for sEMG activation of the PFM to detect the occurrence of SUI, we performed receiver operating characteristic (ROC) curve analysis (with Youden’s index). Results: Significantly lower results were obtained for all PFM measurements in women with SUI. The optimum diagnostic cutoff for “baseline” was 3.7 μV (area under curve (AUC), 0.63), “quick flicks” was 9.15 μV (AUC, 0.84), “contractions” was 11.33 μV (AUC, 0.80), “static hold” was 9.94 μV (AUC, 0.84), and “rest” was 3.89 μV (AUC, 0.63). Conclusions: Measuring sEMG activity in the PFM may be a useful diagnostic tool to confirm the absence of SUI. We can expect that the sEMG activity of subjects with SUI will be lower than that of healthy people. In order to determine appropriate reference values for assessing sEMG activity data in the PFM, it is now necessary to conduct multicenter studies.

Magnetomyographic Recordings of Pelvic Floor Activity During Pregnancy and Postpartum: A Novel Non-invasive Approach

The levator ani muscles (LAM) are integral to pelvic floor support and injury to this muscle complex has been associated with pelvic floor disorders, but our ability to evaluate their neuromuscular integrity is limited. During pregnancy, gravidas undergo systemic functional and anatomic modifications, including pelvic floor muscular adaptations. Magnetomyography (MMG) is a novel and non-invasive tool to passively measure the magnetic fields generated by depolarization activity of muscles and offers a unique method to evaluate the LAM. We collected serial MMG data in a pregnant woman with singleton gestation. Pregnant woman performed LAM contractions (Kegels) with intervening rest periods. Kegel signals were isolated by using the frequency dependent subtraction (SUBTR) and independent component analysis (ICA) methods. Concurrent body-surface electromyography (EMG) was used to evaluate for accessory-muscle recruitment by placing bipolar electrodes on the perineum, abdomen, and thigh. Amplitude and spectral-related indicators were computed across moderate intensity MMG Kegel epochs: root-mean square (RMS) amplitude, power spectrum density (PSD) and relative PSD (rPSD) in three frequency bands. Indicators were extracted from two pregnancy recordings and one postpartum. Parameters were represented in terms of gestation and postpartum weeks. We observed that postpartum RMS Kegel amplitudes had lower values than seen in pregnancy. Changes in spectral indicators were observed between pregnancy and postpartum.

Intraday and interday reliability of pelvic floor muscles electromyography in continent woman

AIMS

Vaginal surface electromyography (sEMG) is a tool used for the diagnosis and therapeutic intervention of urinary incontinence. Current sEMG systems differ in regard to electrode arrangement and data reproducibility. The aim of this study was to determine the intrasession, intraday, and interday reliabilities of sEMG parameters using a probe with circumferential electrode-position.

METHODS

The intrasession, intraday, and interday reliabilities of maximum isometric voluntary contractions (MVC) of the pelvic floor muscles were assessed for 19 healthy continent women. Three sEMG parameters that are used to describe muscle activity were verified: maximal EMG (EMG_max ), mean over 500 ms around EMG_max (EMG_A0.5 ), and mean over 2 seconds during MVC plateau (EMG_A2-4 ). Relative and absolute reliability parameters were calculated, and the statistical methods described by Bland and Altman were applied to the data.

RESULTS

We observed substantial reliabilities for all obtained parameters (EMG_max , EMG_A2-4 , and EMG_A0.5 ) in regard to the intrasession measurements (ICC = 0.93-0.97; CI = 0.86-0.99). Overall, the intraday reliability has been moderate (ICC = 0.64-0.75; CI = 0.27-0.90). EMG_max (ICC = 0.75; CI = 0.45-0.90) and EMG_A2-4 (ICC = 0.73, CI = 0.42-0.89) were higher than EMG_A0.5 (ICC = 0.64; CI = 0.27-0.85). However, the interday reliability was only fair for EMG_max (ICC = 0.48; CI = 0.04-0.77) and EMG_A0.5 (ICC = 0.51; CI = 0.07-0.78) but moderate for EMG_A2-4 (ICC = 0.65; CI = 0.28-0.85).

CONCLUSIONS

This intrasession, intraday, and interday reliability results are similar to the results reported in the literature using probes with longitudinally oriented bars. The mean sEMG signal over 2 seconds (EMG_A2-4 ) exhibited the highest reliability and is recommended for further studies. The interday reliability might be enhanced by considering the menstruation cycle.

Activity of Deep and Superficial Pelvic Floor Muscles in Women in Response to Different Verbal Instructions: A Preliminary Investigation Using a Novel Electromyography Electrode

INTRODUCTION

Verbal instructions are used clinically to encourage activation of the pelvic floor muscles (PFM). Whether separate layers of PFM activate differently in response to instructions remains unknown.

AIM

To test the hypotheses that (i) instructions that aimed to bias activity of a specific muscle layer would increase activation of the targeted layer to a greater extent than the other layer, (ii) activity of individual PFM layers would differ between instructions, and (iii) PFM activity would be symmetrical for all instructions.

METHOD

PFM electromyography (EMG) was recorded using custom-designed surface electrodes in 12 women without PFM dysfunction. The electrode included 4 pairs of recording surfaces orientated to measure EMG from deep and superficial PFM on each side. 3 submaximal contractions were performed for 5 seconds in response to 7 verbal instructions. Root-mean-squared EMG amplitude was calculated for 1 second during the period when participants most closely matched the target activation level. A repeated-measures anova was used to test whether PFM EMG differed between instructions and between regions. The EMG increase of individual muscles relative to that of the reference muscle [deep/right PFM] was compared to no change with t-tests for single samples.

MAIN OUTCOME MEASURE

PFM EMG amplitude.

RESULTS

Superficial PFM EMG was greater than deep PFM for all instructions (P = .039). 2 instructions induced the greatest amplitude of EMG for the superficial PFM: "squeeze the muscles around the vaginal opening as if to purse lips of your mouth" and "draw the clitoris in a posterior direction" (P = .036). Asymmetry was found in the deeper PFM in 3 instructions designed to bias the superficial PFM.

STRENGTH & LIMITATIONS

This preliminary study recorded activation of deep and superficial PFM layers in females with a custom-designed novel electrode. Some cross-talk of recording between muscle layers is possible but unlikely to impact the major findings.

CONCLUSION

Verbal instructions used to teach PFM contractions can influence their pattern of activity. This study provides preliminary evidence that, in a selection of verbal instructions, the superficial PFM activates more than the deep PFM, and that the deep PFM can have asymmetrical activation. Aljuraifani R, Stafford RE, Hall LM, et al. Activity of Deep and Superficial Pelvic Floor Muscles in Women in Response to Different Verbal Instructions: A Preliminary Investigation Using a Novel Electromyography Electrode J Sex Med 2019;16:673-679.

An International Classification of Function, Disability and Health (ICF)-based investigation of movement impairment in women with pelvic organ prolapse

Background

There is little evidence on movement impairment of the abdominal and pelvic floor muscles (PFM) in women with pelvic organ prolapse (POP).

Objectives

The aim of this study was to determine the movement impairments and interactions between the PFM and abdominal muscles in POP.

Method

The PFM and abdominal muscles of 100 conveniently sampled South African women with POP were assessed by ultrasonography, electromyography (EMG), the PERFECT scale, Sahrmann scale and a Pressure Biofeedback Unit (PBU). A demographic questionnaire determined contextual factors (exercise and medical history) and Visual Faces Scale pain intensities. Data were analysed descriptively and with Spearman and Pearson correlation coefficients.

Results

Participants (59 ± 9.31 years) were mostly unemployed (80%), physically inactive (85%), with comorbidities, heart or vascular disease, hypothyroidism and depression. The mean levator hiatus at rest (56.38 mm, standard deviation [SD] 9.95), thickness (5.1 mm, SD 1.41), amount of movement (4.28 mm, SD 6.84), strength (level 1.89, SD 1.13) and endurance (4.04 s, SD 3.32) of the PFM indicated dysfunction. Median values of zero were found for the Sahrmann scale (interquartile [IQ] range [0–1]) and PBU (IQ range [0–2]) and 10.95 µV for abdominal EMG (IQ range [7.9–17.8]). Pelvic floor muscle strength, endurance, movement and EMG activity correlation was fair (r > 0.4, p < 0.001), as was PFM strength, endurance and abdominal muscle function (r > 0.4, p < 0.05).

Conclusion

Movement impairment of local and global stability and mobility functions of PFM and abdominal muscles was present, as well as correlations between these functions. Addressing these impairments may affect the identified contextual factors (socio-economic, psychological and lifestyle factors) and the possible activity limitations and participation restrictions in patients with POP. Further research is needed to investigate these interactions.

Clinical implications

The findings suggest that assessment and management of patients with POP might need to be based on a comprehensive neuro-musculoskeletal assessment and a holistic approach. Standardised protocols for patients with pelvic floor dysfunction (PFD) should therefore be used with caution. Randomised controlled trials should investigate patient-specific and holistic intervention approaches.

Characterizing pelvic floor muscles activities using magnetomyography

AIMS

To characterize levator ani muscle (LAM) activity in nulligravidas using magnetomyography (MMG) and define MMG characteristics associated with LAM activity with and without accessory muscle contributions.

METHODS

MMG data were collected from eight nulligravidas during rest and voluntary LAM contractions (Kegels) of varying intensity. We utilized simultaneous vaginal manometry and surface electromyography (sEMG) to evaluate for accessory muscle recruitment. Moderate Kegel (MK) MMG trials were sub-selected based on the presence or absence of accessory muscle interaction. Amplitude and spectral-related indicators were calculated across MK epochs: root-mean square (RMS) amplitude, percentage amplitude relative to rest, and relative power spectrum density (rPSD) in three frequency bands (low, middle, high). Ternary diagram characterized rPSD from selected Kegels and ROC analysis was performed to identify cut-points to differentiate MKs from interacting MKs.

RESULTS

Nineteen MMG recordings were obtained. Amplitude and spectral parameters were significantly different between isolated and interacting MK epochs. Mean RMS and power values of the isolated MK were, respectively, 120.66 ± 43.8 fT and 1.72 ± 1.44 (T² /Hz)*10^-28 . Amplitudes of MK were 64% and 117 higher than baseline activities for the isolated and interacting epochs, respectively. ROC curves reveled cut-off points on low and middle frequency bands that achieved perfect separation (ROC-AUC = 1.0) between isolated and interacting MK.

CONCLUSIONS

Our study demonstrates that MMG, a novel biomagnetic technique, allows precise detection and characterization of normal female pelvic floor function. Results show that isolated moderate voluntary contraction of the LAMs produces distinct MMG amplitude and spectral characteristics compared with Kegels involving co-activation of other muscle groups.

Crosstalk considerations in studies evaluating pelvic floor muscles using surface electromyography in women: a scoping review

PURPOSE

Surface electromyography (sEMG) using intravaginal probes is of widespread use for assessing pelvic floor muscles (PFM) activity in women. Although considered as a reliable method, its validity has been called into question due to the presence of a phenomenon called crosstalk. Crosstalk is described as the recording of sEMG activity originating from neighboring muscles rather than coming exclusively from the muscles being investigated. The purpose of this review was to provide an overview of existing literature about crosstalk during intravaginal surface electromyographic recordings.

METHODS

A scoping review was performed according to the Arksey and O'Malley framework. An electronic search was conducted on six relevant databases. Additionally, authors were directly contacted to identify grey literature. Data extraction consisted of descriptive numeric analysis as well as thematic analysis, which were conducted by two independent reviewers.

RESULTS

Forty-nine references written by 34 authors coming from 13 different countries constitute the body of evidence of the present review. Eight main themes have been identified through the thematic analysis. The included material varies greatly in terms of methodology, approach to the crosstalk problem and depth of analysis.

CONCLUSIONS

A gap in knowledge affecting the validity of the current sEMG investigation methods was identified. Literature addressing the crosstalk problem is scarce and often flawed. Definitive conclusions are regularly drawn from an insufficient basis of evidence. Further research is, therefore, deeply necessary, although it remains unclear whether this issue can be solved at all with current technology.

Relationship between lower limb position and pelvic floor muscle surface electromyography activity in menopausal women: a prospective observational study

Objectives

In physiotherapeutic practice, special attention is being given to the reciprocal anatomical, physiological, and biomechanical relationship of the pelvis and the structures connected to it. However, the scientific literature shows mainly the theoretical information about their mutual connections. The lack of information about these relations from a practical aspect coupled with the paucity of scientific papers on the impact of posture changes on the pelvic floor led the authors to conduct this study. The primary aim of this study was to compare the resting and functional bioelectrical activities of pelvic floor muscles (PFMs) depending on three different positions of the lower limbs (positions A, B, and C) in the supine position.

Materials and methods

This was a prospective observational study evaluating resting and functional activities of the PFM depending on the position of the lower limbs. The study was carried out at the Department and Clinic of Urology, University Hospital in Wroclaw, Poland and the target group were women in the menopausal period. Bioelectrical activity of PFM was recorded using a surface electromyographic instrument in the supine position. Results of the values obtained in A, B, and C positions were compared using a one-way analysis of variance.

Results

In position A, the average resting surface electromyography (sEMG) activity of PFM was 6.9±2.6 µV; in position B, the result was 6.9±2.5 µV and in position C, the resting sEMG activity was 5.7±1.8 µV (P=0.0102). The results of the functional bioelectrical activity of PFM were as follows: position A – 20.3±11.8 µV, position B – 19.9±10.6 µV, and position C – 25.3±10.9 µV (P=0.0104).

Conclusion

The results showed that in the supine position, the PFM achieved the lowest resting activity and the highest functional activity. Therefore, the supine position can be recommended for the diagnosis and therapy of weakened PFM.

Assessment of bioelectrical activity of synergistic muscles during pelvic floor muscles activation in postmenopausal women with and without stress urinary incontinence: a preliminary observational study

OBJECTIVE

Muscles such as adductor magnus (AM), gluteus maximus (GM), rectus abdominis (RA), and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI), and the relationship between contraction of these muscles and pelvic floor muscles (PFM) has been established in previous studies. Synergistic muscle activation intensifies a woman's ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM) during resting and functional PFM activation in postmenopausal women with and without SUI.

MATERIALS AND METHODS

This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16) and continent women (n=14). The bioelectrical activity of PFM and SPFM (AM, RA, GM) was recorded with a surface electromyographic instrument in a standing position during resting and functional PFM activity.

RESULTS

Bioelectrical activity of RA was significantly higher in the incontinent group than in the continent group. These results concern the RA activity during resting and functional PFM activity. The results for other muscles showed no significant difference in bioelectrical activity between groups.

CONCLUSION

In women with SUI, during the isolated activation of PFM, an increased synergistic activity of RA muscle was observed; however, this activity was not observed in asymptomatic women. This may indicate the important accessory contribution of these muscles in the mechanism of continence.

Pelvic floor muscle electromyography during different running speeds: an exploratory and reliability study

PURPOSE

Stress urinary incontinence (SUI) affects women of all ages including young athletes, especially those involved in high-impact sports. To date, hardly any studies are available testing pelvic floor muscles (PFM) during sports activities. The aim of this study was the description and reliability test of six PFM electromyography (EMG) variables during three different running speeds. The secondary objective was to evaluate whether there was a speed-dependent difference between the PFM activity variables.

METHODS

This trial was designed as an exploratory and reliability study including ten young healthy female subjects to characterize PFM pre-activity and reflex activity during running at 7, 9 and 11 km/h. Six variables for each running speed, averaged over ten steps per subject, were presented descriptively, tested regarding their reliability (Friedman, ICC, SEM, MD) and speed difference (Friedman).

RESULTS

PFM EMG variables varied between 67.6 and 106.1 %EMG, showed no systematic error and were low for SEM and MD using the single value model. Applying the average model over ten steps, ICC (3,k) were >0.75 and SEM and MD about 50 % lower than for the single value model. Activity was found to be highest in 11 km/h.

CONCLUSION

EMG variables showed excellent ICC and very low SEM and MD. Further studies should investigate inter-session reliability and PFM reactivity patterns of SUI patients using the average over ten steps for each variable as it showed very high ICC and very low SEM and MD. Subsequently, longer running distances and other high-impact sports disciplines could be studied.

[Evaluation of the electromyography activity of pelvic floor muscle during postural exercises using the Wii Fit Plus©. Analysis and perspectives in rehabilitation]

INTRODUCTION

The aim of this work was to evaluate the effect of postural awareness by using the Wii Fit Plus© on the quality of the baseline (automatic) activity of the pelvic floor muscles (PFM) measured by intravaginal surface electromyography (sEMG).

METHODS

Four healthy continent female subjects, all able to perform a voluntary contraction, undertook 2 sets of 3 various exercises offered by the software Wii Fit Plus© using the Wii balance board© (WBB): one set without any visual control and the second set with postural control and sEMG visual feedback. Simultaneously, we recorded the sEMG activity of the PFM.

RESULTS

Mean baseline activity of PFM in standing position at start was 2.87 mV, at submaximal voluntary contraction the sEMG activity raised at a mean of 14.43 mV (7.87-21.89). In the first set of exercises on the WBB without any visual feedback, the automatic activity of the PFM increased from 2.87 mV to 8.75 mV (7.96-9.59). In the second set, with visual postural and sEMG control, mean baseline sEMG activity even raised at 11.39 mV (10.17-11.58).

CONCLUSION

Among women able of a voluntary contraction of PFM, visualisation of posture with the help of the WBB and of sEMG activity of the PFM during static and dynamic Wii Fit Plus© activities, may improve the automatic activation of the PFMs.

LEVEL OF EVIDENCE

4.

The evaluation of bioelectrical activity of pelvic floor muscles depending on probe location: a pilot study

Objectives. The main objective was to determine how the depth of probe placement affects functional and resting bioelectrical activity of the PFM and whether the recorded signal might be dependent on the direction in which the probe is rotated. Participants. The study comprised of healthy, nulliparous women between the ages of 21 and 25. Outcome Measures. Bioelectric activity of the PFM was recorded from four locations of the vagina by surface EMG and vaginal probe. Results. There were no statistically significant differences between the results during functional sEMG activity. During resting sEMG activity, the highest bioelectrical activity of the PFM was observed in the L1 and the lowest in the L4 and a statistically significant difference between the highest and the lowest results of resting sEMG activity was observed (P = 0.0043). Conclusion. Different electrodes placement during functional contraction of PFM does not affect the obtained results in sEMG evaluation. In order to diagnose the highest resting activity of PFM the recording plates should be placed toward the anterior vaginal wall and distally from the introitus. However, all of the PFM have similar bioelectrical activity and it seems that these muscles could be treated as a single muscle.