Comparison of Smoothness during Gait between Community Dwelling Elderly Fallers and Non-Fallers Using Power Spectrum Entropy of Acceleration Time-Series

抄録

[Purpose] We have proposed in a previous paper a novel indicator of smoothness using the power spectrum entropy of acceleration time-series during movement. In this paper, we describe this indicator's ability to distinguish between fallers' and non-fallers' gait in community dwelling elderly. This novel indicator is simple to use and can directly evaluate gait. [Subjects] Two hundred and fifty-one subjects (age = 71.0 7.7) were categorized fallers (39) and non-fallers (191) based on their histories (21 were unknown). [Methods] Grip strength, walking speed and the functional reach test, were used as convenient indicators, and the entropy of spectrum of acceleration during gait were measured and compared between fallers and non-fallers. [Results] Significant differences were found in the entropy of the fastest gait as well as in the other indices (p<.05). We also examined the correlation between entropy and grip strength (Spearman's ρ = -.35, p<.01). Correlations of entropy with the other indices were also low. [Conclusion] These results imply that entropy provides useful information, not found in the other indices, on body function in relation to falling.