The relationship between physical function in the elderly and judgment error in walking speed.

[Purpose] "Judgment error," defined as a difference between the actual and the imagined performance, is often observed in elderly persons. The aims of this study were to assess subjective judgment errors in elderly persons, and to evaluate the relationship between physical function and judgment error in walking speed. [Subjects and Methods] A total of 106 community-dwelling elderly individuals participated. Subjects observed video footage of a model walking an obstacle course, and were asked to subjectively compare the model's gait speed with their own gait speed. When the subjective comparison differed from the actual difference, it was considered as a judgment error. Physical function was compared between those with and without judgment error. [Results] Significant interaction effects between the actual performance and subjective perception were found for the walking time on the obstacle course and the Activities-specific Balance Confidence Scale score (utilized as an index of self-confidence in own balance ability and a fear of falling). [Conclusion] The results demonstrate that some elderly persons tend to overestimate their balance and ambulation function compared to another person, even though they had low physical function and low self-confidence in terms of balance. These elderly individuals might have a high risk of accidents.