[1
]
Department of Community Medicine and Rehabilitation, Umeå University, Vårdvetarhuset,
901 87 Umeå, Sweden; Umeå School of Sport Sciences, Umeå University, IKSU sport, 901
87 Umeå, Sweden. Electronic address: lars.berglund@umu.se.
[2
]
Department of Surgical and Perioperative Sciences, Umeå University Hospital, 901 85
Umeå, Sweden; Norrlandskliniken Health Care Centre, Glimmervägen 5 E, 907 40 Umeå,
Sweden.
[3
]
Division of Health and Rehabilitation, Department of Health Science, Luleå University
of Technology, 971 87 Luleå, Sweden.
[4
]
Department of Community Medicine and Rehabilitation, Umeå University, Vårdvetarhuset,
901 87 Umeå, Sweden; Umeå School of Sport Sciences, Umeå University, IKSU sport, 901
87 Umeå, Sweden.