Abstract des Autors

Virtual time to contact (VTC) is a measure of postural stability that estimates the virtual time it would take to reach an individual’s stability boundary. This study aimed to validate VTC as measured by a depth sensor and determine whether VTC from the depth sensor distinguishes between older adult fallers and nonfallers compared with a force platform. VTC was assessed in 10 young and 20 older adults by having participants lean in a circular direction followed by 5 balance tests: eyes open, dual task, eyes open foam, eyes closed, and eyes closed foam. Spearman rank correlations and Bland–Altman plots were conducted to determine validity, and receiver operating characteristic curves were constructed to discriminate between fallers and nonfallers. Significant correlations were found in the dual task (P = .03), eyes open foam (P < .01), and eyes closed foam conditions (P = .05). The depth sensor discriminated between fallers and nonfallers in the eyes open (P = .02), dual task (P = .03), and eyes open foam conditions (P = .04). VTC was in agreement between the 2 devices, and VTC derived from a depth sensor can be used to discriminate between older adult fallers and nonfallers during challenging balance conditions.