Erratum to: Int Urogynecol J

DOI 10.1007/s00192-013-2189-5

We found a mathematical error in sarcomere length (Ls) measurements in the original publication. Upon detection of the error, sarcomere lengths were re-measured from the original slide-mounted samples, and also in newly dissected fiber bundles from the same specimens to confirm accuracy. Architectural parameters were then recalculated using corrected Ls and all statistical analyses were repeated using corrected data. The revised calculations affected the absolute values only and showed that the pelvic floor muscles (PFMs) do not have sarcomeres shorter than other human skeletal muscles. Importantly, there are no changes in the major conclusion of the article regarding the functional subspecialization of the individual PFMs. A table containing the revised values and the adjusted Figs. 2 and 3 are presented below.

Complete data for coccygeus (C), iliococcygeus (IC), and pubovisceralis (PV) muscles, expressed as means ± SEM

Muscle

Mass (g)

L fn (mm)

L s (μm)

PCSA (cm 2 )

C

3.91 ± 0.48

42.95 ± 3.48

2.52 ± 0.06

0.87 ± 0.08

IC

4.89 ± 0.38

57.97 ± 5.29

2.64 ± 0.07

0.83 ± 0.07

PV

6.39 ± 0.98

78.19 ± 7.39

2.77 ± 0.12

0.79 ± 0.08

P-values *

C vs IC

0.025

0.0061

0.89

0.53

C vs PV

0.019

0.0002

0.1

0.71

IC vs PV

0.16

0.0005

0.7

0.92

Lfn, Fiber length normalized to optimal sarcomere length (Ls); PCSA, physiological cross-sectional area. *P-values derived from repeated-measures ANOVA, followed by Tukey’s pairwise comparisons

Fig. 2 Structural and biochemical properties of human pelvic floor muscles. Values are means ± standard error of the mean (SEM). *Muscle is different from the other two muscles (P = 0.05). PCSA, physiological cross-sectional area; C, coccygeus muscle; IC, iliococcygeus muscle; PV, pubovisceralis muscle

figure a

Fig. 3 Normalized fiber length and physiological cross-sectional area (PCSA) for human pelvic floor muscles. Values are means ± standard error of the mean (SEM)

figure b