Received: 8 November 2018
Accepted: 22 May 2019
First Online: 10 June 2019
Ethics Approval and Consent to Participate
: The study was approved by the ethical committee of the University of Jyväskylä, Finland, and the study was performed in accordance with the standards of ethics outlined in the Declaration of Helsinki. Written informed consent was obtained from all voluntary subjects before the beginning of the study.
: Not applicable
: The authors, Pekka Matomäki, Vesa Linnamo, and Heikki Kyröläinen, declare that they have no competing interests.