title: Functional implications of postural disequilibrium due to lead exposure.
abstract: Measurement of postural equilibrium has been employed as an indirect indicator of functional status of the nervous systems of 109 children (mean age: 5.8 +/- 0.78 years) from the Cincinnati Lead Program Project. The geometric mean blood lead for the first five years of life (PbB05) was 11.9 +/- 1.5 micrograms/dL. Postural sway associated with upright balance was noninvasively quantitated with a microprocessor-based force platform and four tasks performed for 30 sec each by the subjects. A covariate-adjusted multiple regression analysis showed statistically significant associations between PbB05 and the postural sway for the task requiring primarily vestibular and/or proprioceptive systems input, implying potential functional impairment. These findings raised several new issues which are addressed here: (1) A dynamic task has been developed to further test the effect of perturbing those afferents' functional capabilities. (2) A method has been developed to quantitate the stability boundary of each subject to better characterize the limits of functionally-safe postural sway. (3) There is a need to perform the postural sway in a shorter duration than 30 sec so that children younger than five years of age can be tested for early identification of Pb-induced functional impairment of postural equilibrium.
authors.affiliation: Department of Environmental Health, University of Cincinnati Medical Center, Ohio 45267-0056.
authors.forename: A
authors.initials: A
authors.lastname: Bhattacharya
authors.forename: R
authors.initials: R
authors.lastname: Shukla
authors.forename: K N
authors.initials: KN
authors.lastname: Dietrich
authors.forename: J
authors.initials: J
authors.lastname: Miller
authors.forename: A
authors.initials: A
authors.lastname: Bagchee
authors.forename: R L
authors.initials: RL
authors.lastname: Bornschein
authors.forename: C
authors.initials: C
authors.lastname: Cox
authors.forename: T
authors.initials: T
authors.lastname: Mitchell
mesh_terms: D002648:Child; D002675:Child, Preschool; D006801:Humans; D007855:Lead Poisoning / Q000503:physiopathology*; D004856:Postural Balance / Q000187:drug effects*; D011187:Posture / Q000502:physiology*