Evidence-Based: Physical Therapy Pelvic Floor

CLINICAL RECOMMENDATIONS (Visual observation and palpation)





Fig. 5.1 During vaginal palpation the physiotherapist (PT) instructs the patient about how to perform a contraction correctly (squeeze around my finger and try to lift the finger inwards) and tells her how well she is able to do it and also about coordination skills and strength. With encouragement most patients are able to contract harder.


PFM assessment using observation

• Inform and explain the procedure to the patient.

• Teach the patient how to contract the PFM by use of models, anatomical drawings and imagery.

• After the patient has undressed, ask the patient to lie down on the bench with hips and knees bent and shoulder width apart (crook lying). Cover pelvic area with a towel. Support legs of patient (one leg against the wall, the other leg support with one hand).

• Allow some time for patient to practice before observing the contraction.

• Ask the patient to breathe normally and then lift the perineum inwards and squeeze around the openings without any movement of the pelvis or visible contraction of the gluteal or hip-adductor muscles. A small drawing in of the lower abdomen by transverses abdominis with the PFM contraction is accepted. Observe the patient’s attempt to contract and register how the contraction was performed (correct, no contraction, inconclusive, straining).

• If there is an observable contraction, give positive feedback and explain that you will palpate to register action of the deeper muscles, and coordination and strength of the contraction. If you are not able to observe inward movement, explain that this is common at the first attempt, and that it is not always easy to assess from the outside, and that you need to conduct a vaginal palpation to be sure whether there is a contraction or not.

VAGINAL PALPATION

Vaginal palpation (Fig. 5.1) is used to:

1. assess the ability of the patient to contract and relax the PFM correctly;

2. measure PFM muscle strength via a maximal occlusive and lifting force (assessing the person’s attempt to conduct a maximum voluntary contraction), ability to sustain a contraction (endurance) or perform a number of repeated contractions (endurance);

3. assess other elements of PFM, such as resting tone, the ability to fully relax after a contraction, coordination with lower abdominal muscles, symmetry of right and left PFM contraction, scarring and adhesions and the presence of pain, speed and sequence of recruitment of levator ani with the perineal muscles, and transverse and anteroposterior diameters of the urogenital hiatus. As there is yet no evidence for the responsiveness or reliability of measurement of these other elements of muscle parameters, they will not be discussed further in this chapter. The ICS Clinical Assessment Group has proposed qualitative scales of measurement for some of these parameters (absent, partial, full), but here has been a lack of psychometric testing of these scales or development of more responsive scales. This is an area needing further research. Kegel described vaginal palpation as a method to evaluate the ability to perform a correct contraction. He placed one finger in the distal one-third of the vagina and asked the woman to lift inwards and squeeze around the finger. Kegel did not use this method to measure PFM strength. He classified the contraction qualitatively as correct or not. In addition, he developed the ‘perineometer’, a pressure manometer, to measure PFM strength through vaginal squeeze pressure Van Kampen reported that after Kegel first described vaginal palpation as a method to evaluate PFM function, more than 25 different palpation methods have been developed. Some examiners use one, and others two fingers. Worth and Brink have evaluated pressure, duration, muscle ‘ribbing’, and displacement of the examiner’s finger in a specific scoring system. This system has mainly been used by American nurses. There has been no systematic research to determine the best method of palpation to assess ability to contract, or any of the parameters of muscle strength, endurance, or power. Laycock has developed the modified Oxford grading system to measure PFM strength, and this seems to be the system mostly used by PTs to assess PFM strength in clinical practice.

Responsiveness

The Oxford grading system has been modified from the Medical Research Council scale which suffers from poor responsiveness and non-linearity. One of the difficulties of measurement using the modified Oxford scale is that it produces one value for two elements (occlusion and lift) in the one scale. The palpating fingers may not be sensitive enough to differentiate the proportions of occlusion versus lift. To separate these two elements, manometers or dynamometers can be used to evaluate occlusion, and ultrasound to measure the lift component. When the responsiveness of this scale is tested against vaginal squeeze pressure, it should be recognized that only one element, occlusion, is being compared. Bo& Finckenhagen (2001) questioned the responsiveness of the original scale (without + and ) because they did not find that the scale could separate between weak, moderate, good, or strong when comparing measurement of vaginal squeeze pressure. This was supported by Morin comparing vaginal palpation and dynamometry in continent and incontinent women. They found that important overlaps were observed between each category of vaginal palpation. Mean force values differed significantly only between non adjacent levels in palpation ssessment (e.g. between 1 and 3, 1 and 4, 1 and 5, 2 and 4, and 2 and 5 [p < 0.05]).

Frawley found that the Oxford grading scale using + and had lower kappa values in intratest reliability testing and recommended using the original six-point scale in research.

Intra- and inter-rater reliability

The results from studies evaluating intra- and inter-rater reliability of vaginal palpation for strength measurement are conflicting (Bø & Finckenhagen 2001, Frawley et al 2006, Hahn et al 1996, Isherwood & Rane 2000, Jeyaseelan et al 2001, Laycock & Jerwood 2001, McKey & Dougherty 1986). Isherwood & Rane 2000) found high inter-rater reliability whereas Jeyaseelan et al (2001) concluded that signs and the presence of pain, speed and sequence of recruitment of levator ani with the perineal muscles, and ransverse and anteroposterior diameters of the urogenital hiatus.

As there is yet no evidence for the responsiveness or reliability of measurement of these other elements of muscle parameters, they will not be discussed further in this chapter. The ICS Clinical Assessment Group has proposed qualitative scales of measurement for some of these parameters (absent, partial, full), but here has been a lack of psychometric testing of these scales or development of more responsive scales. This is an area needing further research. Kegel described vaginal palpation as a method to evaluate the ability to perform a correct contraction. He placed one finger in the distal one-third of the vagina and asked the woman to lift inwards and squeeze around the finger. Kegel did not use this method to measure PFM strength. He classified the contraction qualitatively as correct or not. In addition, he developed the ‘perineometer’, a pressure manometer, to measure PFM strength through vaginal squeeze pressure. Van Kampen reported that after Kegel first described vaginal palpation as a method to evaluate PFM function, more than 25 different palpation methods have been developed. Some examiners use one, and others two fingers. Worth and Brink have evaluated pressure, duration, muscle ‘ribbing’, and displacement of the examiner’s finger in a specific scoring system. This system has mainly been used by American nurses. There has been no systematic research to determine the best method of palpation to assess ability to contract, or any of the parameters of muscle strength, endurance, or power. Laycock has developed the modified Oxford grading system to measure PFM strength (British Medical Research Council 1943, Laycock 1994), and this seems to be the system mostly used by PTs to assess PFM strength in clinical practice.

Responsiveness

The Oxford grading system has been modified from the Medical Research Council scale which suffers from poor responsiveness and non-linearity. One of the difficulties of measurement using the modified Oxford scale is that it produces one value for two elements (occlusion and lift) in the one scale. The palpating fingers may not be sensitive enough to differentiate the proportions of occlusion versus lift. To separate these two elements, manometers or dynamometers can be used to evaluate occlusion, and ultrasound to measure the lift component. When the responsiveness of this scale is tested against vaginal squeeze pressure, it should be recognized that only one element, occlusion, is being compared. Bø & Finckenhagen questioned the responsiveness of the original scale (without + and ) because they did not find that the scale could separate between weak, moderate, good, or strong when comparing measurement of vaginal squeeze pressure. This was supported by Morin comparing vaginal palpation and dynamometry in continent and incontinent women. They found that important overlaps were observed between each category of vaginal palpation. Mean force values differed significantly only between non adjacent levels in palpation assessment (e.g. between 1 and 3, 1 and 4, 1 and 5, 2 and 4, and 2 and 5 [p < 0.05]). Frawley found that the Oxford grading scale using + and had lower kappa values in intratest reliability testing and recommended using the original six-point scale in research.

Intra- and inter-rater reliability

The results from studies evaluating intra- and inter-rater reliability of vaginal palpation for strength measurement are conflicting, Frawley, Hahn, Isherwood & Rane 2000, Jeyaseelan 2001, Laycock & Jerwood 2001, McKey & Dougherty 1986). Isherwood & Rane (2000) found high inter-rater reliability whereas Jeyaseelan et al (2001) concluded that the modified Oxford grading scale The modified Oxford grading scale is a six-point scale where half numbers of + and can be added when a contraction is considered to fall between two full grades, so it expands to a 15-point scale when both + and are used:

Box 5.1: The modified Oxford grading scale

0 = no contraction

1 = flicker

2 = weak

3 = moderate (with lift)

4 = good (with lift)

5 = strong (with lift)

inter-tester reliability should not be assumed, and needs to be established when two or more clinicians are involved in pre- and post-treatment assessment. Bø & Finckenhagen using the six-point scale and Laycock & Jerwood using the 15-point scale found agreement between testers in only 45% and 45% of the tested cases, respectively. Frawley et al (2005) found 79% complete agreement in both crook lying and supine using the six-point scale but this dropped to 53 and 58%, respectively, using the 15-point scale. They tested intratester reliability of vaginal digital assessment and found good to very good kappa values of 0.69, 0.69, .86, and 0.79 for crook lying, supine, sitting, and standing positions, respectively. In addition, they compared vaginal palpation with vaginal squeeze pressure measurement with the Peritron perineometer and found that the Peritron was more reliable than vaginal palpation.

Devreese developed a new vaginal palpation system assessing muscle tone, endurance, speed of contraction, strength, lift (inward movement) and coordination, and evaluated both superficial and deep PFM. They found high agreement in interobserver reliability in tone (95–100% agreement) and reliability coefficients between 0.75 and 1.00 for measurements of the other parameters above. The scoring system developed is qualitative and open to personal interpretation, but is a first step towards standardizing a measurement system for observation and palpation. Muscle ‘tone’ requires a universally acceptable definition to establish a reliable measurement system, and to differentiate ‘tone’ from ‘stiffness’, ‘contracture’ and ‘spasm’. Simons & Mense have proposed that muscle tone specific to a muscle rather than generalized tone be defined as ‘the elastic and viscoelastic stiffness of a muscle in the absence of motor unit activity’. The elastic component or ‘elastic stiffness’ is measured qualitatively by pressing or squeezing a muscle. However, measurement of the viscoelastic component is more complex and is dependent on the speed at which the muscle is moved using pendular, oscillatory and resonant frequency measurements. These viscoelastic measurements are not possible for the PFM because the PFM do not pass over a joint to allow elongation then shortening. If the PFM are elongated using vaginal palpation to stretch the muscle fibres, the muscle belly is actually being compressed by the examining digit and elastic stiffness is again being measured. One can also discuss how one can assess that there is no motor unit activity. At least for the PFM, there is always electromyographic (EMG) activity except before and during voiding.

Validity

Several investigators have studied criterion validity of vaginal palpation comparing vaginal palpation and vaginal squeeze pressure, Hahn et al 1996, Isherwood & Rane 2000, Jarvis et al 2001, Kerschan-Schindel et al 2002, McKey & Dougherty 1986). Isherwood & Rane (2000) compared vaginal palpation using the Oxford Grading System and compared it with an arbitrary scale on a perineometer from 1 to 12. They found a high kappa of 0.73. In contrast, found a kappa of 0.37 comparing the Oxford grading system with vaginal squeeze pressure. Heitner (2000) concluded that lift was most reliably tested with palpation, and that all other measures of muscle function were better tested with EMG found that there was a better correlation of vaginal palpation and pressure measurement in continent than in incontinent women (r = 0.86 and 0.75, respectively). This was supported by Morin comparing vaginal palpation with dynamometry, finding r = 0.73 n continent and r = 0.45 in incontinent women, respectively.

Lying, sitting or standing?

PFM function and strength is often measured in a supine position, despite the fact that urinary leakage is more common in the upright position with gravity acting on the PFM. Very few studies have addressed measurement in different positions. Devreese investigated inter-rater reliability of clinical observation and vaginal palpation in crook lying, sitting, and standing positions. They found high inter-tester reliability in all positions, but did not report whether there were differences in measurement values in the different positions. Frawley found that vaginal palpation of PFM contraction had moderate to high intratest reliability in crook lying, supine, sitting and standing position. Both Bø & Finckenhagen and Frawley found that PTs and patients preferred testing using vaginal palpation and vaginal squeeze pressure in lying positions. Bø & Finckenhagen found that the testing procedure was easiest to standardize when the patient was supine, and therefore recommend this in clinical practice. For scientific purposes the position of the patient should be chosen according to the research question.

Visual observation and palpation (One or two fingers?)

There is a discussion whether one or two fingers should be used for vaginal palpation and this may depend on factors such as whether the patient is nulliparous and has a narrow vaginal introitus and urogenital hiatus, or whether there is introital discomfort or pain. Hoyte reported increased diameters from nonsymptomatic parous women, to parous women with pelvic organ prolapse (POP). In parous women, vaginal birth may have stretched the PFM and its investing fascia. However, time and PFM training may normalize this in many women. When palpating, the anterior and posterior vaginal walls are always in apposition and in contact with the finger. The lateral vaginal walls expand in the upper vagina at the level of the fornices and above the level of the levator ani. At the PFM level, the lateral diameter of the urogenital hiatus marks the medial borders of the levator ani and these borders may be palpated through the intervening vaginal mucosa. Ghetti stated that intra- and inter-rater reliability of vaginal palpation to assess the diameter of the hiatus needs to be done. In addition, criterion validity between magnetic resonance imaging (MRI)/ultrasound and vaginal palpation of the hiatus has to be established. Putting a muscle on stretch makes it more difficult to perform a maximal contraction. Therefore the aim of palpation should be to gain maximum sensation for the palpation with no stretch. This must not be confused with the fact that a quick stretch can be used to facilitate the stretch reflex. Quick stretch is one technique used by PTs to facilitate a correct PFM contraction if the patients are unable to contract.

Sensitivity and specificity

There are few studies comparing measurement of PFM function and strength in continent and incontinent women using vaginal palpation. Hahn compared 30 continent and 30 incontinent women using vaginal palpation and found that the group of incontinent women had lower scores on palpation test (1.0 0.1) compared to the group of continent women (1.9 0.1) (p < 0.001). Devreese found a significant difference in favour of continent women in speed of contraction, maximum strength and coordination of both superficial and deep PFM, and inward movement of the superficial, but not the deep PFM, assessed with vaginal palpation.

Conclusion

Today most PTs use vaginal palpation to evaluate PFM function because both squeeze pressure and lift can be registered, though with poor discrimination. It is a lowcost method, and is relatively easy to conduct. Vaginal palpation of PFM contraction is recommended as a good technique for use by PTs to understand, teach, and give feedback to patients about correctness of the contraction. Position of the patient, instruction given, and the use of one or two fingers have to be standardized and reported. However, whether palpation is robust enough to be used for scientific purposes to measure muscle strength is questionable. Palpation as a method to detect morphological abnormalities also needs to be tested before being used in clinical assessment and research.

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