title: Relationships between unilateral horizontal and vertical drop jumps and 20 m sprint performance.
abstract: OBJECTIVE
  The purpose of this study was to compare the relationships between horizontal (HDJ) and vertical drop jumps (VDJ) to sprint performance.
  
  
  METHODS
  Exploratory Study.
  
  
  METHODS
  Laboratory.
  
  
  METHODS
  Nineteen male collegiate participants (22.5 ± 3.2 years, 181.1 ± 6.7 cm, 80.3 ± 9.6 kg).
  
  
  METHODS
  All participants performed VDJ and HDJ from a 20 cm height onto an AMTI force platform sampling at 1200 Hz before performing three 20 m sprints. Sprint times (5, 10, 15, 20, 5-10, 10-15, 15-20 m) were measured using a LAVEG speed gun.
  
  
  RESULTS
  All jump and sprint measures showed excellent within session reliability (ICC: 0.954 to 0.99). Pearson's and Spearman's correlations revealed significant (p < 0.01) moderate to high correlations between jump measures and sprint times (R: -0.665 to -0.769). Stepwise multiple regression revealed jump distance normalised by body height (HDJ) was the best predictor for 10, 20, 5-10, 10-15 and 15-20 m sprint times (R(2) = 41%-48%).
  
  
  CONCLUSIONS
  HDJ performance measures provide stronger relationships to sprint performance than VDJ's. Thus, HDJ's should be considered in test batteries to monitor training and rehabilitation for athletes in sprint related sports.
authors.affiliation: University of Salford, United Kingdom.
authors.forename: Daniel
authors.initials: D
authors.lastname: Schuster
authors.affiliation: University of Salford, United Kingdom. Electronic address: P.A.Jones@salford.ac.uk.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Jones
mesh_terms: D056352:Athletes; D054874:Athletic Performance / Q000502:physiology*; D006801:Humans; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D009068:Movement / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D015203:Reproducibility of Results; D012420:Running / Q000502:physiology*; D055815:Young Adult
keywords: Acceleration; Functional tests; Reactive strength; Stretch shorten cycle