Temporal trends in trunk flexor endurance and intra-abdominal pressure in postpartum women.

Women who were lost to follow-up or excluded were significantly younger, more likely to be Hispanic, had less education, and had lower baseline trunk endurance and IAP than the final study population, introducing potential selection bias. Only one measure of trunk muscle function (isometric flexor endurance) was used, which may not capture dynamic trunk stability or other aspects of recovery. Diastasis recti abdominis was not measured, so its potential impact on trunk function in this cohort is unknown. Participants were not instructed on specific muscular or breathing strategies during the test, and natural breathing patterns can lower IAP, which may explain the decrease in pressure over time rather than a true physiological change in abdominal wall function.

The authors declared no conflicts of interest related to the research project.

Do not interpret the decrease in intra-abdominal pressure as a loss of core stability. The study notes that natural breathing patterns during exertion lower IAP compared to breath holding, and women were not instructed on breathing strategies, so this change likely reflects technique or physiological adaptation rather than impaired abdominal function.