Cadenas-Sanchez, C
Henriksson, P
Henriksson, H
Delisle Nyström, C
Pomeroy, J
Ruiz, J R
Ortega, F B
Löf, M
Article History
Received: 19 September 2016
Revised: 4 March 2017
Accepted: 31 March 2017
First Online: 3 May 2017
Competing interests
: The authors declare no conflict of interest.