Correction: BMC Musculoskelet Disord 13, 225 (2012)

https://doi.org/10.1186/1471-2474-13-225

Following the publication of the original article [1], the wrong Additional file 1: Appendix (Supplementary material 1) was originally published with this article; it has now been replaced with the correct file (Supplementary material 2).

The original article [1] has been updated.