title: Accuracy of Jump-Mat Systems for Measuring Jump Height.
abstract: Vertical-jump tests are commonly used to evaluate lower-limb power of athletes and nonathletes. Several types of equipment are available for this purpose.
  
  
  OBJECTIVE
  To compare the error of measurement of 2 jump-mat systems (Chronojump-Boscosystem and Globus Ergo Tester) with that of a motion-capture system as a criterion and to determine the modifying effect of foot length on jump height.
  
  
  METHODS
  Thirty-one young adult men alternated 4 countermovement jumps with 4 squat jumps. Mean jump height and standard deviations representing technical error of measurement arising from each device and variability arising from the subjects themselves were estimated with a novel mixed model and evaluated via standardization and magnitude-based inference.
  
  
  RESULTS
  The jump-mat systems produced nearly identical measures of jump height (differences in means and in technical errors of measurement ≤1 mm). Countermovement and squat-jump height were both 13.6 cm higher with motion capture (90% confidence limits ±0.3 cm), but this very large difference was reduced to small unclear differences when adjusted to a foot length of zero. Variability in countermovement and squat-jump height arising from the subjects was small (1.1 and 1.5 cm, respectively, 90% confidence limits ±0.3 cm); technical error of motion capture was similar in magnitude (1.7 and 1.6 cm, ±0.3 and ±0.4 cm), and that of the jump mats was similar or smaller (1.2 and 0.3 cm, ±0.5 and ±0.9 cm).
  
  
  CONCLUSIONS
  The jump-mat systems provide trustworthy measurements for monitoring changes in jump height. Foot length can explain the substantially higher jump height observed with motion capture.
authors.forename: Basilio
authors.initials: B
authors.lastname: Pueo
authors.forename: Patrycja
authors.initials: P
authors.lastname: Lipinska
authors.forename: José M
authors.initials: JM
authors.lastname: Jiménez-Olmedo
authors.forename: Piotr
authors.initials: P
authors.lastname: Zmijewski
authors.forename: Will G
authors.initials: WG
authors.lastname: Hopkins
mesh_terms: D000293:Adolescent; D000328:Adult; D054874:Athletic Performance; D005080:Exercise Test / Q000295:instrumentation*; D005528:Foot; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D055815:Young Adult
keywords: contact mat; jump performance; modeling; motion capture; open-source technology; reliability