title: Day-time effect on postural stability in young sportsmen.
abstract: BACKGROUND
  stabilometry is commonly used from clinicians and posturologists for stability and postural assessment of patients. In the daily practice a large number of posturologists are usual to control the effect of their treatments on the same subject through stabilometry but tests are not always performed at the same time, so it is necessary to be sure that data are not influenced by the time-of-day. The aim of this study was to evaluate the time-of-day effect on stabilometric parameters and theirs variation.
  
  
  METHODS
  for this aim 61 healty sportsmen performed on four repetitions of the stabilometric test during the same day (morning - evening). Data collected from each test were: centre of pressure sway path length, Naiperian logarithm of the ellipse of confidence area, of the x mean and of the y mean, eccentricity of the ellipse area.
  
  
  RESULTS
  no significant difference was found in any parameter at any time of the day. Intra-class Correlation Coefficient value confirmed the reliability of the stabilometric evaluation in healty subjects (sway path length 0.836 and 0.816 for open and closed eyes, respectively).
  
  
  CONCLUSIONS
  these findings suggest that stabilometry evaluation is not affected by a time-of-day, therefore the test and retest in different time of day is reliable to assess postural sway.
authors: Department of Applied Clinical Sciences and Biotechnologies, University of L'Aquila, Italy.
authors: Luca
authors: L
authors: Russo
authors: Faculty of Medicine and Dental Surgery, Sapienza University of Rome, Italy.
authors: Umberto
authors: U
authors: D'Eramo
authors: University eCampus, Novedrate, Italy ; Tunisian Research Laboratory "Sports Performance Optimization" National Center of Medicine and Science in Sport, Tunis, Tunisia.
authors: Johnny
authors: J
authors: Padulo
authors: Tor Vergata University, Rome, Italy.
authors: Calogero
authors: C
authors: Foti
authors: Faculty of Medicine and Dental Surgery, Sapienza University of Rome, Italy.
authors: Riccardo
authors: R
authors: Schiffer
authors: Faculty of Medicine and Dental Surgery, Sapienza University of Rome, Italy.
authors: Fabio
authors: F
authors: Scoppa
keywords: balance; circadian variation; intra/inter variability; reliability; stabilometry; testing; time of day