Cough-induced urinary incontinence (UI) is common in women and appears to be closely related to the biomechanical and neuromuscular demands of coughing. Coughing is a whole-body task involving coordinated activation of the diaphragm, abdominal muscles, pelvic floor muscles (PFMs), and upper trunk musculature, including the scapular stabilizers. Altered postural control during cough may transiently or chronically affect scapular stability as well as continence [1, 2]. Thus, postural stabilization of the scapulae during coughing has been proposed as a potential strategy to improve continence, but its effects on PFMs activation remain poorly understood.
Aims are to explore surface electromyographic (sEMG) activation peaks of the PFMs between coughing without and with controlled postural stabilization of the scapulae and observe any potential predictors of this change in sEMG activation.

Secondary analyses of a prospective interventional cohort including women with cough-induced UI.
Each participant performed voluntary coughing efforts under two conditions. Control condition: coughing without specific postural stabilization instructions. Experimental condition: coughing associated with postural stabilization instructions for the scapulae aimed at maintaining a neutral posture. In both situations, no voluntary contraction from the PFMs was requested. The intensity of the coughing efforts was controlled by spirometry to ensure their mechanical equivalence. Pelvic floor muscle activity was recorded by sEMG using a vaginal probe. Repeated measurements were compared to verify the absence of fatigue or learning effects, allowing the calculation of a within-subject mean for each condition. Resting scapular postures were assessed with video motion capture by goniometry and inclinometry. The primary comparison between conditions was performed using a paired t-test. A secondary analysis involved dividing the sample into two groups according to the direction of the sEMG response to the intervention, to explore individual response profiles.

Seventeen women with cough-induced UI were analysed. All participants exhibited deviations from normative scapular position at rest. Mean absolute deviations from normative values ranged from 0° to 30° (SD: 7.32°) for rotation (i/eRS) and 0° to 11° (SD: 3.64°) for lateral/medial scapular slide (l/mRS). No significant between-group differences were observed.
The two groups did not differ statistically in terms of  epidemiological characteristics (age, BMI, parity,  UI severity). Only group B had a slightly higher parity values than group A (p=0.17 NS).
For the entire group, no significant difference in mean PFM sEMG peak activity was observed between the control and experimental conditions (p=0.50). Marked interindividual variability was evident. Eight participants (47%, Group A) demonstrated  increase  PFMs sEMG activity with postural stabilization, whereas nine participants (53%, Group B) showed decrease. The effect size of the experimental situation on the group that responded positively was significantly greater (Median [Q1–Q3] = 16.38 μV [9.70–23.07]) than the effect size for the group that reacted negatively (Median [Q1–Q3] = -5.84 μV [1.20–9.51])(p=0.05).

These findings suggest that cough-induced UI patients exhibit significant baseline scapular malalignment, potentially reflecting compensatory adaptations, which may influence both upper trunk stability and PFMs response during coughing.
The maximum sEMG peak reflects the maximum recruitment of motor units. The absence of significant between-group differences suggests that the intervention’s effects may not be uniform across the sample, with substantial inter-individual variability potentially masking group-level trends. Thus, the lack of a global effect does not imply inefficacy, but rather highlights the need for individualized response profiling in future exploratory analyses.

Women with cough-induced UI exhibit heterogeneous PFMs activation responses to scapular postural stabilization during coughing. Two distinct response profiles were identified, with the mean magnitude of PFMs activation increase exceeding three times the magnitude of decrease. These results underscores the potential value of tailored interventions based on scapular-PFMs coupling patterns. This warrant further investigation into predictors to guide personalized rehabilitation strategies.

Muhammed A, Moiz JA, Singla D, Ali MS, Talwar D. Postural abnormalities in phenotypes of chronic obstructive pulmonary disease. Braz J Phys Ther. 2020 Jul-Aug;24(4):325-332
de Lima EdSS, Carneiro EF, Amorim KM, Amorim CF, Andrade AdO, Lucareli PRG, Biasotto-Gonzalez DA, Politti F. Cough-Induced Contraction Response Time and Strength of the Pelvic Floor Muscles Between Women with and Without Stress Urinary Incontinence. Sensors. 2025; 25(18):5914
Smith MD, Coppieters MW, Hodges PW. Postural response of the pelvic floor and abdominal muscles in women with and without incontinence. Neurourol Urodyn. 2007;26(3):377-85