Krogh, K
Emmanuel, A
Perrouin-Verbe, B
Korsten, M A
Mulcahey, M J
Biering-Sørensen, F
Article History
Received: 8 September 2016
Revised: 6 December 2016
Accepted: 11 December 2016
First Online: 14 February 2017
Competing interests
: The authors declare no conflict of interest.