Pelvic floor muscle (PFM) function plays an important role in bladder control. Digital palpation is used to assess the PFMs and surrounding areas at rest and during contraction [1]. Manual evaluation of the PFM provides information about pelvic floor strength, endurance, and integrity. Most research on assessment of PFM strength has been conducted in clinical and/or symptomatic populations, with limited evaluation in the general female population and across the lifespan. We aimed to describe PFM function and assess association with age and parity, two factors strongly associated with bladder control, among community-dwelling women.

RISE FOR HEALTH (RISE) is a regionally-representative cohort study of 3,422 women recruited from 8 geographic areas in the United States conducted by the Prevention of Lower Urinary Tract Symptoms (PLUS) Research Consortium. A subset of RISE participants (n=520) agreed to participate in a clinical visit that included a modified pelvic examination of PFM strength [2]. Participants completed a survey consisting of demographics and clinical history including urinary symptoms. Circumferential digital palpation by trained examiners (physicians and advanced practice providers [i.e., nurse practitioners, physician assistants, nurse midwives]) was performed to assess voluntary contraction of the PFMs [2]. The index finger was used to test the muscle midline (6 o’clock position) and bilaterally (right and left side) at the 4 o’clock and 8 o’clock positions. Participants were asked to sustain the muscle contraction for five seconds followed by relaxation of equal time. PFM strength was evaluated with an adaptation of the Modified Oxford Grading System (No contraction, Flicker, Weak, Moderate, Good with lift, Strong) [3]. Descriptive statistics were used to summarize participants’ characteristics and proportional logistic regression models were used to estimate the association for age and mode of delivery with PFM strength.

Participants had a mean age of 50.4 years (SD 17.5) and were diverse with respect to race and ethnicity (6.8% Asian,14.6% Black, 71.5% White, 11.8% Hispanic any race), Body Mass Index (BMI) (38% BMI ≥30), and menopausal status (39.7% pre-menopausal, 46.8% post-menopausal). The majority (85.2%) were currently using a hormonal therapy; of those; 32.2% reported taking hormonal contraceptives, 30% used systemic hormone replacement therapy, and 37.8% used vaginal estrogen. Two-hundred sixty-eight (53.4%) participants reported any urinary incontinence (stress, urgency, mixed). Approximately, half (52.5%) were parous. Self-reported medical and surgical history included diabetes (13.5%), anxiety or depression (28.7%), constipation and IBS (18.1%), pelvic organ prolapse (7.3%), uterine fibroids (18.8%), surgery for pelvic organ prolapse (4%), and hysterectomy (17.3%).  Over half (58%) of participants reported never engaging in PFM exercises. Data on PFM strength were obtained from 504/520 women. Sixteen participants did not have a pelvic examination [declined exam-5, unable to continue due to pain-2, examiner not available-4, refused to remove clothing-1, and time constraints-4].
Overall, similar distributions of PFM strength were observed in all three muscle locations tested: left side, midline, and right side (Table 1). Therefore, we used an average of the combined location of PFM scores in all subsequent analyses. The majority of women were able to contract their PFMs (96.5%) with moderate to strong combined strength (67.7%). Increasing age was associated with significantly worse PFM strength (Table 2). No significant associations were observed for parity and parous events.

We describe the distribution of PFM strength in a stratified sample of a non-clinical female population across the lifespan. Findings indicate that the majority of women were able to contract their PFMs, which may be due to examiner training and participant instruction [2]. PFM strength appears to be higher than found in previous studies of nulliparous women and those with stress urinary incontinence. Midline measurement of PFM function appears to be adequate. Almost one-third of women (29.5%) had poor ability to contract their PFMs (weak, flicker or no contraction). Parity and delivery mode was not associated with PFM strength; however, there was a trend toward decreased PFM strength in the older age group. The seemingly high utilization of female hormonal use in this cohort may have influenced the results.

In this regionally-representative cohort study of community-dwelling women with self-reported urinary incontinence, a majority were able to contract their PFMs with moderate to strong combined strength on PFM assessment using a digital evaluation, despite the fact that the majority denied ever practicing pelvic floor muscle exercises.  Health care providers should consider performing PFM assessment on women of all ages to identify those with weaker muscles who may benefit from a PFM exercise program. Future research should evaluate the role of female hormonal use on PFM strength.

1.	Frawley H, Shelly B, Morin M, Bernard S, Bø K, Digesu GA, Dickinson T, Goonewardene S, McClurg D, Rahnama'i MS, Schizas A, Slieker-Ten Hove M, Takahashi S, Voelkl Guevara J. An International Continence Society (ICS) report on the terminology for pelvic floor muscle assessment. Neurourol Urodyn. 2021 Jun;40(5):1217-1260. doi: 10.1002/nau.24658. Epub 2021 Apr 12. PMID: 33844342
2.	Newman, DK, Lowder, JL, Meister, M, Low, LK, Fitzgerald, CM, Fok, CS, Geynisman-Tan, J., Lukacz, ES., Markland, A., Putnam, S., Rudser, K., Smith, AL, Miller, JM, the Prevention of Lower Urinary Tract Symptoms (PLUS) Consortium. (2023) Comprehensive pelvic muscle assessment: Developing and testing a dual e-learning and simulation-based training program. Neurourol Urodyn. June; 42(5): 1036–1054. doi:10.1002/nau.25125
3.	Laycock J. Clinical evaluation of pelvic floor. In: B. Schussler., J Laycock, P Norton, S Stanton(Eds). Pelvic floor re-education. London: Springer-Verlag; 1994, pp. 42-48.