Task-specific differences in respiration-related activation of deep and superficial pelvic floor muscles

Effects of Hypopressive Abdominal Training on Ventilatory Capacity and Quality of Life: A Randomized Controlled Trial

Pelvic floor dysfunctions, associated with alterations in respiratory mechanics and, consequently, quality of life, are the cause of the most frequent gynecological problems. Pelvic floor muscle training emerges as a first-line treatment, with new approaches such as hypopressive exercises. The aim of this study was to analyze the efficacy of an 8-week supervised training program of hypopressive exercises on the pelvic floor and its impact on improving the ventilatory mechanics and quality of life in women. Analysis of the spirometric parameters showed a significant main Group × Time effect for three parameters: the ratio of FEV1/FVC (p = 0.030), the forced expiratory flow at 75% of the expired vital capacity (p < 0.001), and the forced expiratory flow over the middle half of the forced vital capacity (p = 0.005). No statistical significance was found regarding the SF-12 questionnaire components; only differences were found over time in the physical role (p = 0.023), bodily pain (p = 0.001), and vitality (p < 0.010) domains and in the physical component summary score (p = 0.010). After an 8-week intervention of hypopressive exercises, an improvement in the ventilatory and pulmonary capacities can be observed.

Pelvic floor muscle length changes with breathing in males: A preliminary report

The study aimed to identify whether pelvic floor muscles modulate length with breathing, and if any length changes induced by breathing relate to abdominal cavity displacement and intra-abdominal pressure. To investigate these relationships, displacement of pelvic landmarks that related to pelvic floor muscle length using transperineal ultrasound imaging, breath volume, intra-abdominal pressure, abdominal and ribcage displacement, and abdominal and anal sphincter muscle electromyography were measured during quiet breathing and breathing with increased dead-space in ten healthy men. Pelvic floor muscle landmark displacement modulated with ribcage motion during breathing. This relationship was stronger for: i) motion of the urethrovesical junction (puborectalis muscle length change) than the mid-urethra landmark (striated urethral sphincter muscle length change), and ii) dead-space breathing in standing than dead-space breathing in supine or quiet breathing in standing. In most (but not all) participants, the urethrovesical junction descended during inspiration and elevated during expiration. Striated urethral sphincter length changes during the respiratory cycle was independent of intra-abdominal pressure. In summary, breathing involves pelvic floor muscle length changes and is consistent with the role of these muscles during respiration to aid maintenance of continence, lung ventilation and/or provision of support to the abdominal cavity. Clinicians who train pelvic floor muscles need to be aware that length change of pelvic floor muscles is expected with breathing.

Pelvic floor dysfunction and electrophysiology in postpartum women at 6-8 weeks

Objective: To investigate the incidence of pelvic floor dysfunction (PFD) and electrophysiological indicators in postpartum women at 6-8 weeks and explore the influence of demographic characteristics and obstetric factors. Methods: A survey questionnaire collected information about the conditions of women during their pregnancy and puerperal period and their demographic characteristics; pelvic organ prolapse quantitation (POP-Q) and pelvic floor muscle electrophysiology (EP) examination were conducted in postpartum women at 6-8 weeks. Results: Vaginal delivery was a risk factor for anterior pelvic organ prolapse (POP) (OR 7.850, 95% confidence interval (CI) 5.804-10.617), posterior POP (OR 5.990, 95% CI 3.953-9.077), anterior and posterior stage II POP (OR 6.636, 95% CI 3.662-15.919), and postpartum urinary incontinence (UI) (OR 6.046, 95% CI 3.894-9.387); parity was a risk factor for anterior POP (OR 1.397,95% CI 0.889-2.198) and anterior and posterior stage II POP (OR 4.162, 95% CI 2.125-8.152); age was a risk factor for anterior POP (OR 1.056, 95% CI 1.007-1.108) and postpartum UI (OR 1.066, 95% CI 1.014-1.120); body mass index (BMI) was a risk factor for postpartum UI (OR 1.117, 95% CI 1.060-1.177); fetal birth weight was a risk factor for posterior POP (OR 1.465, 95% CI 1.041-2.062); and the frequency of pregnancy loss was a risk factor for apical POP (OR 1.853, 95% CI 1.060-3.237). Conclusion: Pelvic floor muscle EP is a sensitive index of early pelvic floor injury. The changes in muscle strength and fatigue degree coexist in different types of postpartum PFD, and each has its own characteristics.

Effects of motor stimulation of the tibial nerve on corticospinal excitability of abductor hallucis and pelvic floor muscles

Introduction

Peripheral nerve stimulation can modulate the excitability of corticospinal pathways of muscles in the upper and lower limbs. Further, the pattern of peripheral nerve stimulation (continuous vs. intermittent) may be an important factor determining the modulation of this corticospinal excitability. The pelvic floor muscles (PFM) are crucial for maintaining urinary continence in humans, and share spinal segmental innervation with the tibial nerve. We explored the idea of whether the neuromodulatory effects of tibial nerve stimulation (TibNS) could induce effects on somatic pathways to the PFM. We evaluated the effects of two patterns of stimulation (intermittent vs. continuous) on corticospinal excitability of the PFM compared to its effect on the abductor hallucis (AH) muscle (which is directly innervated by the tibial nerve). We hypothesized that intermittent TibNS would increase, while continuous stimulation would decrease, the excitability of both AH and PFM.

Methods

Twenty able-bodied adults (20-33 years of age) enrolled in this study. TibNS was delivered either intermittently (1 ms pulses delivered at 30Hz with an on:off duty cycle of 600:400 ms, for 60 min), or continuously (1 ms pulses delivered at 30Hz for 36 min) just above the motor threshold of the AH. We randomized the order of the stimulation pattern and tested them on separate days. We used surface electromyography (EMG) to record motor-evoked responses (MEP) in the PFM and AH following transcranial magnetic stimulation (TMS). We generated stimulus-response (SR) curves to quantify the changes in peak-to-peak MEP amplitude relative to TMS intensity to assess changes in corticospinal excitability pre- and post-stimulation.

Results and Conclusion

We found that TibNS increased corticospinal excitability only to AH, with no effects in PFM. There was no difference in responses to continuous vs. intermittent stimulation. Our results indicate a lack of effect of TibNS on descending somatic pathways to the PFM, but further investigation is required to explore other stimulation parameters and whether neuromodulatory effects may be spinal in origin.

Rumba Dance Combined with Breathing Training as an Exercise Intervention in the Management of Stress Urinary Incontinence in Postmenopausal Women: A Randomized Controlled Trial

Purpose: Stress urinary incontinence (SUI) refers to involuntary leakage from the urethra, synchronous with exertion/effort, sneezing or coughing, which has a negative effect on quality of life. Studies have shown that mild-to-moderate physical activities reduce the risk of SUI by multiple mechanisms. The objective of this study was to determine whether the Rumba dance combined with breathing training (RDBT) can reduce the severity of incontinence and improve the quality of life of patients with SUI. Methods: A randomized clinical trial was conducted with women who were sedentary, were postmenopausal, reported mild-to-moderate SUI on a 1-h pad test, were not already engaged in Rumba dance and did not receive estrogen replacement therapy. The patients were randomly assigned to the RDBT group (n = 13) or the control group (n = 11). The intervention included 90 min of RDBT three times per week for 16 weeks, and the vaginal resting pressure (VRP), pelvic floor muscle (PFM) strength and endurance, 1-h pad test, International Consultation on Incontinence Questionnaire—Urinary Incontinence Short Form (ICIQ—UI SF), and the Incontinence Quality of Life Questionnaire (I—QOL) were measured or completed at baseline and 16 weeks. None of the participants reported adverse events. Results: The mean (±SD) age of the participants was 55.75 ± 5.58 years. After 16 weeks, in the RDBT group, the urine leakage on the 1-h pad test was significantly decreased −2.91 ± 0.49 from the baseline (p = 0.000). The VRP increased from 76.00 ± 16.23 cmH2O to 95.09 ± 18.90 cmH2O (p = 0.000), the PFM endurance of class I (−3.15 ± 1.99% vs. −0.46 ± 0.97%, p = 0.000) and class II (−0.69 ± 0.95% vs. −0.23 ± 0.44%, p = 0.065) increased, and the grades of PFM strength of class I and class II were significantly enhanced (p < 0.01). Finally, the severity of self-reported incontinence (ICIQ—UI SF) significantly decreased from 6.12 ± 2.15 to 3.81 ± 1.68 (p = 0.000), and quality of life (I—QOL) improved from 75.73 ± 11.93 to 83.48 ± 7.88 (p = 0.005). Conclusion: A 16-week RDBT program can increase PFM strength and endurance to reduce the severity of incontinence symptoms and improve the quality of life in patients with SUI, demonstrating the feasibility of recruiting and retaining postmenopausal women with SUI into a RDBT therapeutic program.

Breathing, (S)Training and the Pelvic Floor—A Basic Concept

Background: The current scientific literature is inconsistent regarding the potential beneficial or deleterious effects of high-intensity physical activities on the pelvic floor (PF) in women. So far, it has not been established with certainty whether disparate breathing mechanisms may exert short- or long-term influence on the PF function in this context, although based on the established physiological interrelationship of breathing with PF activation, this seems plausible. Objective: To propose a basic concept of the influence of different breathing patterns on the PF during strenuous physical efforts. Methodical approaches: Review of the recent literature, basic knowledge of classical western medicine regarding the principles of muscle physiology and the biomechanics of breathing, additional schematic illustrations, and magnetic resonance imaging (MRI) data corroborate the proposed concept and exemplify the consequences of strenuous efforts on the PF in relation to respective breathing phases. Conclusion: The pelvic floor muscles (PFMs) physiologically act as expiratory muscles in synergy with the anterolateral abdominal muscles, contracting during expiration and relaxing during inspiration. Obviously, a strenuous physical effort requires an expiratory motor synergy with the PFM and abdominal muscles in a co-contracted status to train the PFM and protect the PF against high intra-abdominal pressure (IAP). Holding breath in an inspiratory pattern during exertion stresses the PF because the high IAP impinges on the relaxed, hence insufficiently protected, PFMs. It seems conceivable that such disadvantageous breathing, if performed regularly and repeatedly, may ultimately cause PF dysfunction. At any rate, future research needs to take into account the respective breathing cycles during measurements and interventions addressing PFM function.

Hypogravity reduces trunk admittance and lumbar muscle activation in response to external perturbations

Reduced paraspinal muscle size and flattening of spinal curvatures have been documented after spaceflight. Assessment of trunk adaptations to hypogravity can contribute to development of specific countermeasures. In this study, parabolic flights were used to investigate spinal curvature and muscle responses to hypogravity. Data from five trials at 0.25 g, 0.50 g, and 0.75 g were recorded from six participants positioned in a kneeling-seated position. During the first two trials, participants maintained a normal, upright posture. In the last three trials, small-amplitude perturbations were delivered in the anterior direction at the T₁₀ level. Spinal curvature was estimated with motion capture cameras. Trunk displacement and contact force between the actuator and participant were recorded. Muscle activity responses were collected by intramuscular electromyography (iEMG) of the deep and superficial lumbar multifidus, iliocostalis lumborum, longissimus thoracis, quadratus lumborum, transversus abdominis, obliquus internus, and obliquus externus muscles. The root mean square iEMG and the average spinal angles were calculated. Trunk admittance and muscle responses to perturbations were calculated as closed-loop frequency-response functions. Compared with 0.75 g, 0.25 g resulted in lower activation of the longissimus thoracis (P = 0.002); lower responses of the superficial multifidus at low frequencies (P = 0.043); lower responses of the superficial multifidus (P = 0.029) and iliocostalis lumborum (P = 0.043); lower trunk admittance (P = 0.037) at intermediate frequencies; and stronger responses of the transversus abdominis at higher frequencies (P = 0.032). These findings indicate that exposure to hypogravity reduces trunk admittance, partially compensated by weaker stabilizing contributions of the paraspinal muscles and coinciding with an apparent increase of deep abdominal muscle activity.NEW & NOTEWORTHY This study presents for the first time novel insights into the adaptations to hypogravity of spinal curvatures, trunk stiffness, and paraspinal muscle activity. We showed that exposure to hypogravity reduces the displacement of the trunk by an applied perturbation, partially compensated by weaker stabilizing contributions of the paraspinal muscles and concomitant increase in abdominal muscle responses. These findings may have relevance for future recommendations for planetary surface explorations.

A Novel Rehabilitative Protocol in the Treatment of Mixed Urinary Incontinence in Women: The Effects of Focused Mechano-Acoustic Vibration

Dysfunctions of the pelvic floor related to mixed urinary incontinence in women are pathologies extremely limiting for patients bodily and psychosocial conditions, altering their quality of life. The aim of this study was to determine the effects of focal mechanical vibrations in mixed urinary incontinence. In this retrospective observational case-control study, 65 patients were randomized and divided into 2 groups: treatment group by focal mechanical vibrations (VISS-10 sessions) (N = 33) and a control group in waiting list (N = 32). Also, both groups received home-based postural ergonomic instructions to reinforce pelvic floor. Data were collected at T0 (baseline), T1 (end of treatment), and T2 (follow-up = after 1 month): rheological muscle parameters were assessed by MyotonPRO respect to evaluate the gluteus maximus muscle. Then, to measure the general disability of the pelvic floor and the impact of urogenital problems on daily activities the Pelvic Floor Disability Index (PFDI-20) and the Pelvic Floor Impact Questionnaire (PFIQ-7) were used. Groups were matched perfectly before treatment for age (58.20 ± 4.37 vs. 58.73 ± 5.19) and BMI (26.15 ± 2.22 vs. 25.85 ± 2.11); for the two-way ANOVA analysis, a difference in gluteus variables over time and between groups except for GMDR (group p-value = 0.60) was showed. The two-way ANOVA shows statistically significant effects of treatment and time for PDFI-20 and PFIQ-7 (p-value <0.001). An improvement in incontinence symptoms and quality of life in the PDFI-20 and PFIQ-7 scores were reported and VISS may favor muscles stiffness for exercises by improving the normalization of basal tone. Our results were encouraging and suggested the use of focal mechanical vibration as a novel tool for treating mix urinary incontinence in women to complete and help the rehabilitative therapeutic protocol.

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.