Characteristics associated with freezing of gait in actual daily living in Parkinson's disease.

[Purpose] Parkinson's disease (PD) patients often freeze in actual daily living but seldom in clinical setting. This study aimed to identify the factors contributing to freezing of gait (FOG). [Subjects and Methods] The participants included 28 adults with PD. Principal component analysis was used to investigate the characteristics of 14 common FOG situations adopted from previous studies. Cluster analysis classified the subjects into four groups. Kruskal-Wallis test was performed to compare the PD Questionnaire-39 mobility dimension between the groups. [Results] The major variables of the first principal component in 14 FOG situations were unfamiliar places, unpredictable schedule changes, entering an automatic door, when another person suddenly crossed, and change in the walking surface. These situations were unrelated to the second principal component. Getting on/off a public transport and crowded places were major variables for the second principal component, and related to both the first and second principal components. Although fatigue was the most frequent FOG situation, not all principal components were influenced. The values of the PD Questionnaire-39 revealed significant differences between the groups. [Conclusion] Actual FOG situations may be categorized into (1) task complexity, (2) both task complexity and emotional factors, and (3) fatigue as decreased attentional resources.