Overactive bladder syndrome is characterized by bothersome urinary urgency, occurring with or without urge urinary incontinence.1 In addition to neurogenic and myogenic factors directly affecting smooth bundles in the bladder wall, the tone and contractile properties of the pelvic floor muscles also influence lower urinary tract function and perceptions of bladder filling and storage. Concomitantly, afferent signals from the urothelium influence pelvic floor muscle tone and function.2 As a result, pelvic floor muscle dysfunction is commonly found in patients with lower urinary tract symptoms, and it should be routinely assessed when evaluating overactive bladder dysfunction.
Pelvic floor dysfunction describes an impairment of tone and/or contractile force within the pelvic floor muscles. The nuances of the muscle dysfunction vary among individuals, but general categories of dysfunction can be defined. The two most common categories associated with overactive bladder dysfunction are high-tone or low-tone pelvic floor muscle dysfunction. This article describes the differential diagnosis of high-tone and low-tone pelvic floor dysfunction and outlines treatment options.3
Pelvic floor muscle function is evaluated by internal manual examination.4 Assessment is conducted by gentle palpation of the muscles intervaginally in the female and transrectally in the male. The practitioner manually assesses pelvic floor tone, sensitivity to pressure, and volitional contraction abilities. Pelvic floor muscle tone is categorized as normal, high, or low. Pain with palpation is noted and can be rated using a scale of 0–4, where 0 indicates absence of pain and 4 indicates severe pain. Similarly, volitional contraction strength is usually graded on a scale of 0–5, where 0 indicates absence of contractile force and 5 indicates optimal contraction strength. Endurance of contraction is measured, with 10 seconds set as a goal. The number of 1-second contractions achievable is noted, 10 being optimal.5
High-tone pelvic floor muscle dysfunction presents as a persistent and elevated resting tone. Intravaginal or intrarectal palpation reveals resistance to stretch. The muscle may feel thick, boggy, or hypertrophied, and taut bands may be palpated. The patient will find manual palpation to be uncomfortable or painful. Volitional contraction will be weakened, and endurance will be diminished. Lower urinary tract symptoms commonly associated with high-tone pelvic floor muscle dysfunction include voiding frequency, bothersome urgency, stress incontinence, pelvic pain, and dyspareunia.6
Internal pelvic floor massage,7 as well as manual treatment addressing pelvic structural imbalances, can reduce high-tone pelvic floor dysfunction and associated bladder symptoms. In the presence of high-tone pelvic floor dysfunction, it is best to consider internal and structural manual treatment before prescription of pelvic floor muscle exercise.8
In the patient with low-tone pelvic floor dysfunction, the practitioner typically finds a thin atrophied muscle, with a wider vaginal vault or lax anal sphincter. Palpation is rarely painful, volitional contractions are weak, and endurance is diminished. Low-tone pelvic floor dysfunction is found more commonly in parturious women and may involve pudendal denervation and connective tissue laxity. Pelvic floor muscle exercise can improve muscle function, assisting in decreasing low-tone pelvic floor symptoms of incontinence, urgency, and frequency.9
1. Lukban JC, Whitmore KE. Pelvic floor muscle re-education treatment of the overactive bladder and painful bladder syndrome. Clin Obstet Gynecol.
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4. Whitmore KE, Kellogg-Spadt S, Fletcher E. Comprehensive assessment of pelvic floor dysfunction. Issues Incontinence.
5. Laycock J, Jerwood D. Pelvic floor muscle assessment: the perfect scheme. Physiotherapy.
6. Weiss JM. Pelvic floor myofascial trigger points: manual therapy for interstitial cystitis and the urgency-frequency syndrome. J Urol.
7. Oyama IA, Rejba A, Lukban JC, et al. Modified Theile massage as therapeutic intervention for patients with interstitial cystitis and high tone pelvic floor dysfunction. J Urol.
8. Lukban JC, Whitmore KE, Kellogg-Spadt S, et al. The effects of manual physical therapy in patients diagnosed with interstitial cystitis, high tone pelvic floor dysfunction and sacroiliac dysfunction. Urology.
9. Handa VL, Harris TA, Ostegard D. Obstetric management to prevent incontinence and pelvic organ prolapse. Obstet Gynecol.