Evaluation of pelvic floor muscle strength using four different techniques

Area of Science:

• Urogynecology
• Pelvic Floor Physical Therapy
• Biomedical Engineering

Background:

• Accurate measurement of pelvic floor muscle (PFM) strength is crucial for diagnosing and treating pelvic floor dysfunction.
• Current assessment techniques may lack the specificity to isolate PFM activity from surrounding musculature.

Purpose of the Study:

• To evaluate the specificity of four techniques (digital palpation, intravaginal EMG, pressure perineometry, perineal ultrasound) in measuring isolated PFM strength.
• To determine if these techniques can differentiate PFM contractions from those involving abdominal, gluteal, or adductor muscles, or the Valsalva maneuver.

Main Methods:

• Sixteen volunteers performed contractions using PFM only, or other muscle groups (abdominal, gluteal, adductor) with and without PFM activation.
• Contraction attempts also included the Valsalva maneuver with and without PFM activation.
• Pelvic floor muscle strength was assessed using digital palpation, intravaginal EMG, pressure perineometry, and perineal ultrasound.

Main Results:

• EMG and pressure perineometry showed non-PFM induced readings in a significant proportion of participants during isolated contractions of abdominal (3/8, 3/8), adductor (6/11, 2/11), and Valsalva maneuvers (4/9, 9/9).
• Digital palpation and perineal ultrasound showed fewer non-PFM induced readings, suggesting greater specificity.
• The Valsalva maneuver particularly confounded pressure perineometry readings (9/9).

Conclusions:

• Intravaginal EMG and pressure perineometry lack the specificity to selectively measure pelvic floor muscle activity.
• These findings suggest that clinicians should exercise caution when interpreting results from EMG and pressure perineometry, especially when assessing isolated PFM function.
• Further research into more specific assessment methods for PFM strength is warranted.