title: Changes in muscle activation following balance and technique training and a season of Australian football.
abstract: OBJECTIVE
  Determine if balance and technique training implemented adjunct to 1001 male Australian football players' training influenced the activation/strength of the muscles crossing the knee during pre-planned and unplanned sidestepping.
  
  
  METHODS
  Randomized Control Trial.
  
  
  METHODS
  Each Australian football player participated in either 28 weeks of balance and technique training or 'sham' training. Twenty-eight Australian football players (balance and technique training, n=12; 'sham' training, n=16) completed biomechanical testing pre-to-post training. Peak knee moments and directed co-contraction ratios in three degrees of freedom, as well as total muscle activation were calculated during pre-planned and unplanned sidestepping.
  
  
  RESULTS
  No significant differences in muscle activation/strength were observed between the 'sham' training and balance and technique training groups. Following a season of Australian football, knee extensor (p=0.023) and semimembranosus (p=0.006) muscle activation increased during both pre-planned sidestepping and unplanned sidestepping. Following a season of Australian football, total muscle activation was 30% lower and peak valgus knee moments 80% greater (p=0.022) during unplanned sidestepping when compared with pre-planned sidestepping.
  
  
  CONCLUSIONS
  When implemented in a community level training environment, balance and technique training was not effective in changing the activation of the muscles crossing the knee during sidestepping. Following a season of Australian football, players are better able to support both frontal and sagittal plane knee moments. When compared to pre-planned sidestepping, Australian football players may be at increased risk of anterior cruciate ligament injury during unplanned sidestepping in the latter half of an Australian football season.
authors.affiliation: The School of Sport Science, Exercise and Health, University of Western Australia, Australia. Electronic address: cyril.donnelly@uwa.edu.au.
authors.forename: C J
authors.initials: CJ
authors.lastname: Donnelly
authors.affiliation: The School of Sport Science, Exercise and Health, University of Western Australia, Australia.
authors.forename: B C
authors.initials: BC
authors.lastname: Elliott
authors.affiliation: The School of Sport Science, Exercise and Health, University of Western Australia, Australia.
authors.forename: T L A
authors.initials: TL
authors.lastname: Doyle
authors.affiliation: Centre for Healthy and Safe Sport, University of Ballarat, Federation University, Australia.
authors.forename: C F
authors.initials: CF
authors.lastname: Finch
authors.affiliation: The School of Sport Science, Exercise and Health, University of Western Australia, Australia; School of Psychology and Exercise Science, Murdoch University, Australia.
authors.forename: A R
authors.initials: AR
authors.lastname: Dempsey
authors.affiliation: The School of Sport Science, Exercise and Health, University of Western Australia, Australia; Centre for Musculoskeletal Research, Griffith Health Institute, Griffith University, Australia.
authors.forename: D G
authors.initials: DG
authors.lastname: Lloyd
mesh_terms: D000293:Adolescent; D001315:Australia; D005538:Football / Q000502:physiology*; D006801:Humans; D007717:Knee / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology; D009119:Muscle Contraction; D053580:Muscle Strength; D018482:Muscle, Skeletal / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods*; D004856:Postural Balance / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology; D013848:Thigh; D055815:Young Adult
keywords: ACL; Exercise; Injury prevention; Knee; Muscle; Prophylactic