Pelvic floor muscle reflex activity during coughing - an exploratory and reliability study

Area of Science:

• Urogynecology
• Biomechanics
• Electrophysiology

Background:

• Activities like coughing increase intra-abdominal pressure, impacting pelvic floor muscles (PFMs).
• Stress urinary incontinence (SUI) is often assessed via coughing, but PFM responses during this action are not well understood.
• Electromyography (EMG) can measure PFM activity, but its reliability during coughing needs investigation.

Purpose of the Study:

• To describe PFM pre-activity and reflexivity during coughing using EMG.
• To examine the reliability of PFM EMG measurements during coughing in healthy women.

Main Methods:

• An exploratory and reliability study involving 11 healthy women.
• EMG was used to record PFM activity during standardized coughs.
• Six EMG variables were analyzed across different time intervals relative to the cough onset, with reliability assessed using intraclass correlation coefficients (ICC), SEM, and MD.

Main Results:

• PFM activity during coughing (35.1–52.2 %EMG) was significantly higher than at rest (24.9±3.7 %EMG).
• Reliability measures showed good to excellent ICC(3,k) (0.67–0.91) but fair to excellent ICC(3,1) (0.40–0.77).
• High SEM (6.1–18.0 %EMG) and MD (16.7–50.0 %EMG) indicated poor reliability for PFM EMG variables during coughing.

Conclusions:

• PFM exhibit increased activity, including pre-activity and reflex responses, during coughing.
• Despite increased activity, PFM EMG measurements during coughing demonstrate low reliability, suggesting significant heterogeneity.
• The findings indicate that coughing may be an unreliable clinical test for assessing PFM function due to variability and potential muscle crosstalk.