Paula T Hakala*, Lea A Saarni, Raija-Leena Punamäki, Marjut A Wallenius, Clas-Håkan Nygård and Arja H Rimpelä
* Corresponding author: Paula T Hakala paula.t.hakala@uta.fi
BMC Musculoskeletal Disorders 2012, 13:41 doi:10.1186/1471-2474-13-41