Frisch, J
Rey-Rico, A
Venkatesan, J K
Schmitt, G
Madry, H
Cucchiarini, M
Article History
Received: 23 June 2015
Revised: 13 September 2015
Accepted: 19 October 2015
First Online: 19 November 2015
Competing interests
: The authors declare no conflict of interest.