Fig. 4

T2W sagittal section of the pelvic magnetic resonance imaging depicting the normal pubococcygeal line (PCL) (yellow), H line (red) and the M line (blue). PCL is between the inferior margin of symphysis pubis and the tip of the coccyx. H-line is the distance between the inferior border of the pubic symphysis and the posterior wall of the rectum at the level of the anorectal junction and indicates the width of the levator hiatus. M-line is the vertical line drawn perpendicularly from the PCL to the posterior end of the H line. M line indicates the degree of decent of the levator hiatus or the degree of pelvic floor laxity