Comparison on gait characteristics between controlled and free-living conditions in old adults

Gait is an important biomarker of functional conditions and gait characteristics can help us assessing health conditions and managing progression of diseases. Most of the existing research study the gait in controlled condition, such as clinical tests. In this paper, we study the gait characteristics in free-living conditions in old adults and compare them with that in controlled conditions, i.e., Timed Up and Go (TUG) test. 65 subjects (12 patients with mobility impairment and 53 healthy controls) are recruited from elderly nursing institutions. The video data are collected from them in TUG test and free-living conditions and the 9 gait characteristics, including gait speed, are extracted from the data. Two-sample tests and independence test based on copula entropy are conducted on the extracted data to compare the characteristics in two conditions. Comparison results show that gait characteristics, such as gait speed, pace, speed variability, etc., in daily life are different from that of in TUG test. In daily life, people tend to have slow gait speed, smaller pace and speed variability, more frequent stride, and smaller acceleration range than in TUG test. We also found that gait speed, pace, and speed variability have stronger dependence with TUG score in the 3 conditions (TUG, daily life, and both) and that other 5 characteristics have stronger dependence with TUG score in both condition than in each condition. The comparison in this study suggests that TUG and daily life conditions are complementary with each other, and that TUG test can be considered as intervention on the movement state of human.