Hip and Pelvic Floor Muscle Strength in Women with and without Urgency and Frequency Predominant Lower Urinary Tract Symptoms

Abstract

Background: Urgency and frequency are common lower urinary tract symptoms (UF-LUTS) in women. There is limited evidence to guide physical therapist-led treatment.

Objectives: To compare hip and pelvic floor muscle strength between women with and without UF-LUTS. We hypothesized women with UF-LUTS would demonstrate 1) diminished hip external rotator and abductor strength and 2) equivalent pelvic floor strength and diminished endurance compared to controls.

Study design: A matched case-control study.

Methods: Women with UF-LUTS (cases) and controls were matched on age, body mass index (BMI), vaginal parity. Examiner measured participants' 1) hip external rotator and abductor strength via dynamometry (maximum voluntary effort against fixed resistance) and 2) pelvic floor muscle strength (peak squeeze pressure) and endurance (squeeze pressure over a 10 second hold) via vaginal manometry. Values compared between cases and controls with paired-sample t-tests (hip) or Wilcoxon signed rank tests (pelvic floor).

Results: 21 pairs (42 women): Hip external rotation (67.0 ± 19.0 N vs 83.6 ± 21.5 N; P=0.005) and hip abduction strength (163.1 ± 48.1 N vs 190.1 ± 53.1 N; P=0.04) were significantly lower in cases than controls. There was no significant difference in pelvic floor strength (36.8 ± 19.9 cmH₂0 vs 41.8 ± 21.0 cmH₂0; P=0.40) or endurance (234.0 ± 149.6 cmH₂0*seconds vs 273.4 ± 149.1 cmH₂0*seconds; P=0.24).

Conclusion: Women with UF-LUTS had weaker hip external rotator and abductor muscles, but similar pelvic floor strength and endurance compared to controls. Hip strength may be important to assess in patients with UF-LUTS, further research is needed.

Keywords: case-control studies; musculoskeletal system; overactive bladder; urinary frequency; urinary urgency.

Figure 1.. Hip External Rotator Isometric Make Test

With hip flexed to 90 degrees, participants externally rotated their hip as strongly as possible against fixed resistance of the strap. Peak force in Newtons was measured by a handheld dynamometer inside the strap at 4cm proximal to the medial malleolus.

Figure 2.. Hip Abductor Isometric Make Test

With hip in neutral flexion, abduction and rotation, participants abducted their hip as strongly as possible against fixed resistance of the strap. Peak force in Newtons was measured by a handheld dynamometer inside the strap at 4cm proximal to the lateral knee joint line.

Figure 3.. Hip External Rotator Strength in women with and without urgency and frequency predominant lower urinary tract symptoms (UF-LUTS)

*Significantly greater in Control compared to UF-LUTS, per one-tailed paired t-test X represents mean, line represents 50^th percentile, error bars represent minimum and maximum

Figure 4.. Hip Abductor Strength in women with and without urgency and frequency predominant lower urinary tract symptoms (UF-LUTS)

*Significantly greater in Control compared to UF-LUTS, per one-tailed t-test X represents mean, line represents 50^th percentile, error bars represent minimum and maximum

Figure 5.. Pelvic Floor Muscle Strength - Peak Vaginal Squeeze Pressure (cmH₂0) in women with and without urgency and frequency predominant lower urinary tract symptoms (UF-LUTS)

^☨No significant paired differences, per two-tailed Wilcoxon signed ranks test X represents mean, line represents 50^th percentile, error bars represent minimum and maximum

Figure 6.. Pelvic Floor Muscle Endurance – Vaginal Squeeze Pressure over 10 second hold (cmH₂0*seconds) in women with and without urgency and frequency predominant lower urinary tract symptoms

^☨No significant paired differences, per one-tailed Wilcoxon signed ranks test X represents mean, line represents 50^th percentile, error bars represent minimum and maximum