Although critical for understanding and simulating pelvic floor muscle function and pathophysiology, the fascicle arrangements of the coccygeus and levator ani remain mostly undetermined. We performed close-range photogrammetry on cadaveric pelvic floor muscles to robustly quantify surface fascicle orientations. The pelvic floor muscles of 5 female cadavers were exposed through anatomic dissections, removed en bloc, and photographed from every required angle. Overlapping images were mapped onto in silico geometries and muscle fascicles were traced manually. Tangent vectors were calculated along each trace; interpolated to define continuous, 3D vector fields; and projected onto axial and sagittal planes to calculate angles with respect to the pubococcygeal line. Contralateral and ipsilateral pelvic floor muscles were compared within each donor (Kuiper’s tests) and using mean values from all donors (William-Watsons tests). Contralateral muscles and all but one ipsilateral muscle pair differed significantly within each donor (p < 0.001). When mean values were considered collectively, no contralateral or ipsilateral statistical differences were found but all muscles compared differed by more than 10° on average. Close-range photogrammetry and subsequent analyses robustly quantified surface fascicle orientations of the pelvic floor muscles. The continuous, 3D vector fields provide data necessary for improving simulations of the female pelvic floor muscles.
Bibliographical noteFunding Information:
The authors thank the individuals who donated their bodies to the University of Minnesota’s Anatomy Bequest Program for the advancements of education and research. We would like to acknowledge funding from the National Science Foundation Graduate Research Fellowship Program Grant #1747452 and the National Institute of Health/National Institute of Aging RO3AG050951.
WB is employed by Bayer U.S. LLC, Radiology R&D at the time of submission/publication, SA receives investigator-initiated research funding from Renovia Inc. for work unrelated to this project, and MA is on the Medical Advisory Board, Renovia, Inc. and receives an Editorial stipend from the American Journal of Obstetrics and Gynecology (AJOG). All other authors report no conflicts of interest.
© 2021, Biomedical Engineering Society.
Copyright 2021 Elsevier B.V., All rights reserved.
- Close-range photogrammetry
- Muscle fascicles
- Vector fields
PubMed: MeSH publication types
- Journal Article