RT Journal Article SR Electronic JF British Journal of Sports Medicine JO Br J Sports Med FD BMJ Publishing Group Ltd and British Association of Sport and Exercise Medicine SP 623 OP 624 DO 10.1136/bjsm.2009.065078 VO 43 IS 8 A1 Schwellnus, Martin P YR 2009 UL http://bjsm.bmj.com/content/43/8/623.abstract AB