title: The effect of external ankle support on the kinematics and kinetics of the lower limb during a side step cutting task in netballers.
abstract: BACKGROUND
  Excessive knee valgus moments are considered to be a risk factor for non-contact injuries in female athletes. Knee injuries are highly prevalent in netballers and are significant in terms of cost and disability. The aim of the study was to identify if changes in external ankle support mechanisms effect the range of motion and loading patterns at the ankle and knee joint during a sidestep cutting manoeuvre in high performance netball players.
  
  
  METHODS
  Netballers with no previously diagnosed ankle or knee injury (n = 10) were recruited from NSW Institute of Sport netball programme. Kinematic and kinetic data were collected simultaneously using a 3-D Motion Analysis System and a force platform to measure ground reaction forces. Players performed repeated side step cutting manoeuvres whilst wearing a standard netball shoe, the same shoe with a lace-up brace and a high-top shoe.
  
  
  RESULTS
  The brace condition significantly reduced ankle joint ROM in the sagittal plane by 8.9° ± 2.4 when compared to the standard netball shoe (p = 0.013). No other significant changes were seen between conditions for either kinematic or kinetic data. All shoe conditions did however produce knee valgus moments throughout the cutting cycle that were greater than those considered excessive in the previous literature (0.59 Nm/kg-Bwt).
  
  
  CONCLUSIONS
  The results show that an external ankle support brace can be used to reduce the ROM at the ankle in the sagittal plane without affecting the loading of the joints of the lower limb. Internal varus moments generated at the knee during the task were however greater than values reported in the literature to classify excessive knee joint moments, regardless of the condition. All netballers exhibited lower extremity patterns and alignments previously associated with increased peak external valgus moments including; increasing hip abduction, peak hip flexion and internal rotation during early contact and high laterally directed ground reaction forces. Increased external valgus knee loads have been strongly linked to the development of non-contact injuries at the knee in female athletes and could highlight a potential mechanism for the development non-contact knee injuries in netballers performing side step cutting tasks.
authors.affiliation: Postgraduate Medical Institute, Faculty of Medical Science, Anglia Ruskin University, Chelmsford, UK ; Discipline of Exercise and Sport Science, Faculty of Health Science, The University of Sydney, Sydney, Australia.
authors.forename: Andrew John
authors.initials: AJ
authors.lastname: Greene
authors.affiliation: School of Health and Sport Sciences, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Kragujevac, Queensland Australia.
authors.forename: Max Christian
authors.initials: MC
authors.lastname: Stuelcken
authors.affiliation: Discipline of Exercise and Sport Science, Faculty of Health Science, The University of Sydney, Sydney, Australia.
authors.forename: Richard Murray
authors.initials: RM
authors.lastname: Smith
authors.affiliation: Department of Kinesiology, KU Leuven, Leuven, Belgium ; Chair of Health Innovation and Technology, Fontys University of Applied Sciences, Eindhoven, Netherlands.
authors.forename: Benedicte
authors.initials: B
authors.lastname: Vanwanseele
keywords: Biomechanics; External ankle support; Internal valgus moment; Knee joint loading; Netball; Sidestep cutting