Invariant sway properties in children

The ability to maintain upright body posture depends on the biomechanical p roperties of a body and on the execution of control programs. The aim of th is study was to determine how the structural growth of the human body, betw een ages 7-18, affects spontaneous sway parameters and to determine how the visual feedback positional task changes body sway parameters. The selected parameters of postural sway were evaluated in 57 children aged 7-18, while they stood with their feet together for 30 s. The experiment consisted of two different tasks: free standing with no feedback (No feedback), and free standing with additional Visual feedback (Feedback). No statistically sign ificant correlation between sway parameters and developmental factors (body height, body mass, and age) in the No Feedback task was found. Statistical ly significant correlations were found between age and most of the sway par ameters in the Feedback task. The execution of voluntary feedback resulted in an increase in the total sway (20%), while the total area decreased near ly two-times. The invariance of sway amplitude supports the view that the s ame activation patterns can be utilized by children aged 7-18, despite the changes in body dimensions. (C) 2000 Elsevier Science B.V. All rights reser ved.