title: Triple-hop distance as a valid predictor of lower limb strength and power.
abstract: BACKGROUND
  Hop tests are functional tests that reportedly require strength, power, and postural stability to perform. The extent to which a triple-hop distance (THD) test measures each of these characteristics is relatively unknown.
  
  
  OBJECTIVE
  To determine the extent to which the THD predicts performance on clinical measures of power, strength, and balance in athletic individuals.
  
  
  METHODS
  Within-subjects correlational study.
  
  
  METHODS
  Station-based, preseason screening of athletes.
  
  
  METHODS
  Forty National Collegiate Athletic Association Division I-AA men's and women's soccer student-athletes (20 women, 20 men; age = 20.0 +/- 1.4 years, height = 172.8 +/- 9.2 cm, mass = 71.9 +/- 8.9 kg).
  
  
  METHODS
  As part of a comprehensive preseason screening of athletes, participants completed the Balance Error Scoring System (BESS) test, 3 trials each of the THD and vertical jump, and 5 repetitions each of concentric isokinetic quadriceps and hamstrings strength testing at 60 degrees /s and 180 degrees /s. Bivariate correlations and linear regression analyses determined the extent to which THD (cm) predicted each of the strength, power, and balance measures.
  
  
  METHODS
  Maximal vertical jump height (cm), total BESS error scores, and quadriceps (Quad(60), Quad(180)) and hamstrings (Ham(60), Ham(180)) isokinetic maximum peak torque (Nm) at 60 degrees /s and 180 degrees /s, respectively.
  
  
  RESULTS
  Triple-hop distance was a strong predictor of vertical jump height, explaining 69.5% of the variance (P < .01). THD also predicted 56.7% of the variance in Ham(60) (P < .01), 55.5% of the variance in Ham(180) (P < .01), 49.0% of the variance in Quad(60) (P < .01), and 58.8% of the variance in Quad(180) (P < .01). No relationships between THD and BESS scores were noted.
  
  
  CONCLUSIONS
  Triple-hop distance is a useful clinical test to predict an athlete's lower extremity strength and power. Although THD was not a predictor of static balance, further research is needed to examine its relationship with more dynamic balance tests.
authors.affiliation: The University of North Carolina at Greensboro, Greensboro, NC 27402-6170, USA.
authors.forename: R Tyler
authors.initials: RT
authors.lastname: Hamilton
authors.forename: Sandra J
authors.initials: SJ
authors.lastname: Shultz
authors.forename: Randy J
authors.initials: RJ
authors.lastname: Schmitz
authors.forename: David H
authors.initials: DH
authors.lastname: Perrin
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D007866:Leg / Q000502:physiology*; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D011187:Posture; D012916:Soccer / Q000502:physiology*; D013223:Statistics as Topic