Dear Professor Chapple,
We completely agree with the contention of Bo et al. 1 that practice should not be changed until there is sufficient evidence from clinical trials to confirm the benefit. However, we were very surprised and disappointed by the large number of major errors in the reporting of previous work in this systematic review.
As few studies have yet considered the inclusion of abdominal muscle activation in rehabilitation programs for pelvic floor muscle (PFM) dysfunctions, the authors have included a review of the physiological basis for this proposed addition to clinical intervention. The basis for the intervention is that activity of the PFM and associated elevation of the levator plate often accompany activity of the deep abdominal muscle, transversus abdominis (TrA), during voluntary activation of TrA and during functional tasks. 2,3 Conversely, it is argued that excessive activity of the more superficial muscles (such as the obliquus abdominis externus (OE)) is associated with greater intra-abdominal pressure and potential for descent of the pelvic floor, which is potentially negative for pelvic floor function. Unfortunately the authors have inaccurately reported the results of many studies, and therefore misrepresent these concepts. We comment on the main inaccuracies below.