RT Journal Article SR Electronic T1 Crystal Palace National Sports Centre--London, UK. 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 10 OP 12 DO 10.1136/bjsm.24.1.10 VO 24 IS 1 A1 R Macdonald YR 1990 UL http://bjsm.bmj.com/content/24/1/10.abstract AB