Relationship between force platform and two functional tests for measuring balance in the elderly

BACKGROUND: Clinical and laboratory methods have been developed to assess the different dimensions of postural control with the aim to increase the clinical relevance of decisions about balance deficit. Objectives: The purpose of this study was to correlate the force platform measurements with two functional tests used to evaluate balance in elderly. METHODS: A total of 124 physically independent elderly volunteers participated in this study. Subjects performed the following three tests: 1) a traditional functional balance test, named the one-leg standing test, which measures the time in seconds at this position; 2) a functionalagility/dynamic balance test, which quantifies the total time in seconds that a subject canstand up from a chair and move as quickly as possible around two cones; and 3) an unipodal balance test on a force platform. RESULTS: The one-leg standing test yielded a mean of 12 seconds (SD=9 s), while the mean time observed in the functional agility/dynamic balance test was 26 seconds (SD=6 s). The correlations between the balance parameters of force platform and two functional tests varied between -0.28 and 0.20, which shows a weak association between them. CONCLUSIONS: Our results support the idea that these functional tests do not necessarily furnish the same information regarding balance mechanisms as the force platform. This study contributes to the evaluation of balance in elderly and suggests that functional tests should be used with caution especially in regards to the purposes of the research and when conducting clinical assessments of the elderly.