title: Factors affecting jump performance in professional Australian rules footballers.
abstract: OBJECTIVE
  This study examined factors contributing to jump performance in professional Australian Rules Football (ARF) players.
  
  
  METHODS
  Thirty-two ARF players performed a countermovement jump (CMJ) and were divided into groups based on jump performance: high calibre (HC) or low calibre (LC). During CMJ assessment, force, rate of force development, movement velocity and power were measured. Physical measures included mass, height, age, lower body strength, eccentric utilization ratio and leg stiffness (Kleg). HC and LC groups were compared to determine the variables contributing to jump performance and correlation and regression analyses also aided in identifying such variables. CMJ height was higher in the HC group (P<0.001).
  
  
  RESULTS
  The HC group demonstrated a higher CMJ velocity (9.8%, P=0.004) and CMJ power (14.4%, P=0.042) when compared to the LC group. Further, the HC group demonstrated 7.5% higher Kleg than the LC group (P=0.019). Spearman's rho correlations demonstrated moderate-large relationships between jump height and strength, velocity and power, while the regression analysis revealed velocity was the sole predictive variable of jump performance. Jumping performance clearly differs within a group of professional ARF athletes.
  
  
  CONCLUSIONS
  Movement velocity appears to be an important factor contributing to jump performance; however, lower body power and Kleg are also important for jump performance.
authors.affiliation: Faculty of Health, University of Technology, Sydney, Sydney, Australia - mitchell.woods86@gmail.com.
authors.forename: M A
authors.initials: MA
authors.lastname: Woods
authors.forename: M L
authors.initials: ML
authors.lastname: Watsford
authors.forename: B P
authors.initials: BP
authors.lastname: Cavanagh
authors.forename: E C
authors.initials: EC
authors.lastname: Pruyn
mesh_terms: D000328:Adult; D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D001315:Australia; D005538:Football; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D009068:Movement; D053580:Muscle Strength / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D012044:Regression Analysis; D013647:Task Performance and Analysis