Background: stabilometry is commonly used from cliniclans 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 subkect 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 tim-of-day effect on stabilometric parameters and theirs variation.

Methods: for this aim 61 healthy 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 eclipse of confidence area, of the x mean and of the y mean, eccentricity of the eclipse 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 healthy subjects .

Conclusion: these findings suggest that stabilometry evalutation is tnot affected by a time-of the day therefore the tests and retest in different time of the day is reliable to assess postural sway.