Strength of pelvic floor in men: reliability intra examiners

Introduction: The obtaining of urinary continence is due to the strength of the pelvic floor muscles (MAPs) at the moment of muscle contraction, when there are sudden increases in intra-abdominal pressure, which increases urethral closure pressure and decreases the possibility of urinary loss. Objective: To verify the reliability, type: stability, intra-examiner, of the measure of the strength of MAPs held with Peritron. Methods: Test and retest study to assess the intra-rater reliability of Peritron to measure the strength of MAPs. The sample consisted of 36 male patients, mean age 65.3 ± 7.2 years, all with urinary incontinence (UI) after radical prostatectomy. The physical therapist conducted a training for familiarization with the procedures of MAPs strength assessment with Peritron for two weeks. The strength of MAPs was measured by a perineometer of the Peritron brand (PFX 9300®, Cardio-Design Pty. Ltd, Baulkham Hills, Australia, 2153). Results: The intraclass correlation coefficient (ICC) was equal to 0.99; P = 0.0001. The typical measurement error (ETM) was equal to 3.1 cmH2 O and ETM% of 4. Conclusion: Peritron showed high reliability for measuring the strength of MAPs in men, both for clinical practice and for the production of scientific knowledge. It should be noted that such measures were carried out in stability, so it is suggested that in internal consistency reliability is equivalent.

the State University of Rio de Janeiro, UERJ, RJ-Brazil, in the Pelvic Physiotherapy sector of the Urology Outpatient Clinic of the Federal Hospital of Rio de Janeiro (HFSE), drafted in accordance with the Guidelines for Reporting Reliability and Agreement Studies (GRRAS) [13].All procedures followed the Brazilian guidelines and standards for research involving human beings set forth in Resolution 466 of December 12, 2012 from the National Council of Health [14] and its approval was given by the consubstantiated opinion of protocol nº 06436712.0.0000.5287.

Study design
This was a test and retest study to evaluate the intrarater reliability of Peritron to measure the strength of MAPs in men.

Participants
Thirty-six male patients were included in the study; mean age was 65.3 ± 7.2 years, all of them with sphincteric UI consequent to retropubic radical prostatectomy surgery, with the maximum postoperative time of up to six months; who used 2 to 5 disposable protectors per day.Patients were excluded from the study when they presented symptoms of urinary tract infection; symptoms of lower urinary tract obstruction; anal fistula; previous radiotherapy; and when they did not undergo transurethral resection of the prostate.
The patients, after being referred from the HFSE Urology to the Pelvic Physiotherapy Clinic, underwent an assessment of the strength of the MAPs made by a physiotherapist specialized in Pelvic Physiotherapy, at the same time, in the same place and in the same environmental conditions.The physiotherapist underwent training to familiarize themselves with the strengths of the MAP with Peritron for two weeks, with the physiotherapist experienced in the use of the equipment.

Introduction
The assessment of the strength of the pelvic floor muscles (MAPs) provides the perception of the contraction capacity of these muscles, however it is not an easy task and so far no study has been performed to verify the reliability of an instrument to measure contraction force of these muscles in men [1].The contraction force of the MAPs may contribute to urinary continence, when there are sudden increases in intra-abdominal pressure, with increased urethral closure pressure and a decrease in the possibility of urinary loss [1 -3].
The assessment of the state of a muscle at rest and during maximal voluntary muscle contraction is necessary when re-training a muscle, which makes it possible to compare clinical data before and after an intervention with muscle exercises [4].The strength of the MAPs is important for evaluation, prescription and follow-up of programs aimed at restoring urinary continence resulting from radical prostatectomy [5 -8].
The evaluation of the strength of the MAPs by digital palpation, using the modified Oxford Scale, is the evaluation method most used by physiotherapists because it is costless and practical.However, scientifically, it is a questioned condition because the force of contraction is graded subjectively.In addition, the use of the Scale is appropriate only for women [9 -11].
An objective way to evaluate the strength of the MAPs with strong reliability is the perineometry performed from the measurement of the strength of these muscles with the Peritron (ICC = 0.95, 95% CI 0.88-0.98)because the pressure readings are a proxy measure of strength [11,12], which facilitates the prescription and evaluation of the efficacy of treatment to patients.However, the reliability of the measurement of the strength of the MAPs presented was from a study carried out with women and, after a review in the scientific databases MEDLINE, BVS, SciELO, Scirus and Redalyc, no Peritron reliability study for men was found.
In the absence of studies and given the need for a reliable instrument to evaluate the contraction force of the MAPs in men, the objective of this study was to verify the reliability, intra-examiner, of the measurement of the strength of the MAPs, performed with Peritron.

Methods
This study was developed in the Stricto Sensu Post-Graduation Program in Exercise and Sports Sciences of were analyzed in SPSS version 18.0 packages (SPSS Inc., USA) and Statistica 6.0 (StatSoft, USA).

Results
The deviations between test and retest were equal to 0.1 ± 6.5 cmH 2 O, the Bland & Altman confidence limits were -12.7 to 13.0 cmH 2 O.An outlier was excluded because it presented deviation equal to 28.3 cmH 2 O (Figure 1).The first measure of MAP strength (test) was 83.8 ± 52.0 cmH 2 O.The second measure of MAP strength (retest) was 84.5 ± 52.6 cmH 2 O.The intraclass correlation coefficient (ICC) was 0.99; P = 0.0001.The typical measurement error (TME) was 3.1 cmH 2 O and the TME % was equal to 4.

Discussion
The ICC equal 0.99; P = 0.0001, the TME equal 3.1 cmH 2 O and the TME% equal 4 obtained in the present study showed a strong intra-rater reliability for the measurement of strength of the MAPs with the Peritron perineometer.Observing Figure 1, the minimum strength value of MAPs was 3.6 cmH 2 O and maximum of 211.3 cmH 2 O, both with a test and retest difference close to zero, showing that Peritron can be reliable in measuring both levels of high intensity strength of the MAPs.
The above-mentioned reliability of Peritron to measure the strength of MAPs is very important for both research and clinical care of patients.For both situations, MAPs by means of a sensor connected to a portable microprocessor with a latex tube.

Procedures for measuring the strength of MAPs
Patients became familiarized with three contractions and after two or four days the first measurement of strength of the MAPs (test) with Peritron was performed.Two days later, the second measurement of MAP strength (retest) was performed.None of the participants underwent training of pelvic floor muscles prior to participating in the survey or between the two moments of MAP strength measurement.All were able to voluntarily contract and completely relax their MAPs.
The patient was placed in lateral decubitus with knees and hip flexed, naked from the waist down.The physiotherapist introduced the perineometer sensor into the anal canal with one hand and the other hand placed over the abdomen to control the concomitant contraction of this muscle with the MAPs.The anal pressure was then measured with a seamless medical grade silicone elastomer sensor.The sensor is connected to a portable microprocessor with a latex tube, allowing the measurement of the contraction pressure exerted by the pelvic floor musculature in centimeters of water (cmH 2 O), thus quantifying the indirect force of the MAPs.The pressure gauge readings are a proxy measure of force [15].The instrument was calibrated to zero before each measurement.The anal sensor has not been inflated.According to the manufacturer, inflation is an optional feature that can reduce the sensitivity of the sensor response.Patients were instructed to perform three maximal muscle contractions of the pelvic floor with an interval of 30 seconds between them, as reported in a study by Barbosa et al. [12] Hip and adductor hip contractions were discouraged, as was the Valsalva maneuver [11,15] The maximum value of the three contractions was recorded.

Statistical analysis
In order to analyze the intra-assay reliability of the Peritron perineometer, the intraclass correlation coefficient (ICC) and the typical measurement error (TME) [16] were used.The Bland and Altman confidence limits were used for the exclusion of outliers.The data Page 04 of 07 used to evaluate it the strength of the MAPs, but also has the disadvantage of its high cost [29].There are those that are related to the measurement of contraction, such as dynamometry that measures force in Newton (N) or kilogram-force (kgf), a method that would be ideal since it directly measures force, but so far the literature shows, besides studies in women only, the development of speculum dynamometers to collect their own studies which still limits clinical practice [30 -35].
The present study presented as limitations the nonachievement of intra-rater reliability and inter-rater in internal consistency and inter-rater in stability; sample size (n < 50); perineometry is a voluntary test.

Conclusion
From the results of the present study, Peritron showed a high reliability to measure the strength of MAPs in men, both for clinical practice and for the production of scientific knowledge.It should be noted that such measures were performed in stability, therefore, it is suggested that in internal consistency its reliability is equivalent.
the study design and the statistics used showed that both the researcher and the physiotherapist could use Peritron to obtain reliable results in the research and evaluation of patients.
The reliability obtained in the present study was previously replicated in another study with women, which evaluated the strength of the MAPs by vaginal pressure (ICC = 0.95, 95% CI 0.88-0.98)[11,17].In both situations, for both men and women, reliability was adequate for clinical practice, because in addition to being statistically significant (P = 0.0001), the ICC was higher than 0.93 and the TME less than 9%, cutoff points admitted as low risk to this practice [13].
Analyzing the strength of evidence on the basis of a sample size of studies that tested the reliability of Peritron in women, (n = 20) [11] and (n = 19) [17], this study stands out by having a higher sample size (n = 36).
The strength of the MAPs is one of the most important factors for continence, since fast and strong contractions of the MAPs result in the generation of adequate closure pressure in the proximal urethra, which maintains a higher pressure than in the bladder, thus preventing the loss of urine [18].The training of MAPs is defined as a program of repeated voluntary contractions of these muscles, taught and supervised by a health professional and is most commonly used as a physiotherapy treatment for women with stress urinary incontinence, but it is effective with all types of incontinence and is therefore recommended as a first line therapy [19 -21], which is no different for men after radical prostatectomy [21], since the mechanism of continence is also dependent on the strength of the MAPs to increase the pressure of urethral closure, preventing urinary loss.
There are other methods that evaluate the strength of the MAPs, those considered as procedures for measuring the ability of pelvic muscle contraction, such as vaginal palpation, a method widely used clinically, but questioned for being subjective [22 -24], the use of electromyography that measures the potential of action of the motor units that compose the muscle, but which has as a disadvantage beyond the high cost: the capture of the electric potential of muscles close to what is being evaluated -Crosstalk [22,25,26], the ultrasound in which it can be visualized the contraction of the MAPs in the caudal skull direction by the movement of the pelvic organs, but the studies are controversial as to its use for the evaluation of the MAPs, besides its high cost [27,28] and the magnetic resonance that can also be

Figure 1 -
Figure 1 -Bland & Altman confidence limits for MAPs strength measures with Peritron.