Stabilometric parameters are affected by anthropometry and foot placement.
OBJECTIVE
To recognize and quantify the influence of biomechanical factors, namely anthropometry and foot placement, on the more common measures of stabilometric performance, including new-generation stochastic parameters.


METHODS
Fifty normal-bodied young adults were selected in order to cover a sufficiently wide range of anthropometric properties. They were allowed to choose their preferred side-by-side foot position and their quiet stance was recorded with eyes open and closed by a force platform.


BACKGROUND
biomechanical factors are known to influence postural stability but their impact on stabilometric parameters has not been extensively explored yet.


METHODS
Principal component analysis was used for feature selection among several biomechanical factors. A collection of 55 stabilometric parameters from the literature was estimated from the center-of-pressure time series. Linear relations between stabilometric parameters and selected biomechanical factors were investigated by robust regression techniques.


RESULTS
The feature selection process returned height, weight, maximum foot width, base-of-support area, and foot opening angle as the relevant biomechanical variables. Only eleven out of the 55 stabilometric parameters were completely immune from a linear dependence on these variables. The remaining parameters showed a moderate to high dependence that was strengthened upon eye closure. For these parameters, a normalization procedure was proposed, to remove what can well be considered, in clinical investigations, a spurious source of between-subject variability.


CONCLUSIONS
Care should be taken when quantifying postural sway through stabilometric parameters. It is suggested as a good practice to include some anthropometric measurements in the experimental protocol, and to standardize or trace foot position.


CONCLUSIONS
Although the role of anthropometry and foot placement has been investigated in specific studies, there are no studies in the literature that systematically explore the relationship between such BF and stabilometric parameters. This knowledge may contribute to better defining the experimental protocol and improving the functional evaluation of postural sway for clinical purposes, e.g. by removing through normalization the spurious effects of body properties and foot position on postural performance.
Chiari
Lorenzo
L
Biomedical Engineering Unit, Department of Electronics, Computer Science and Systems, University of Bologna, Viale Risorgimento, 2, Italy. lchiari@deis.unibo.it
Rocchi
Laura
L
Cappello
Angelo
A
D000328:Adult; D000886:Anthropometry / Q000379:methods*; D005246:Feedback / Q000502:physiology; D005260:Female; D005528:Foot / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology; D004856:Postural Balance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D011312:Pressure; D011597:Psychomotor Performance / Q000502:physiology*; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012727:Sex Characteristics; D013223:Statistics as Topic; D013269:Stochastic Processes; D013314:Stress, Mechanical; D014796:Visual Perception / Q000502:physiology*