[The influence of wearing a diaper on static and dynamic postural control in the elderly]

To clarify characteristics of static and dynamic postural control in elderly people, postural sway during static standing, during an activity, and static standing after the activity were compared between young and elderly subjects. In this study, the action of raising pants-type diapers was selected as the model activity for the measurement of dynamic postural control ability.

To make differences in the ease of putting on the diapers, their contraction strength around the abdomen was adjusted at 5 levels from loose to tight. Postural sway was measured first during static standing with open and closed eyes and, then, during activity and static standing after activity. The subjects' perceived difficulty in putting on the diapers was also evaluated.

Postural sway tended to be larger in elderly than younger subjects during static standing, but the differences were not significant. Also, postural sway was markedly increased in elderly subjects during the raising of diapers requiring greater effort. In static standing after an action, postural sway also remained increased after putting on diapers requiring greater effort only in the elderly group.

Postural sway increased, indicating a decline in the dynamic postural control ability, during an action in association with its level of difficulty even in elderly people showing no decline in static postural control ability. In addition, dynamic postural control responses appeared to affect subsequent static postural control responses, inducing a decline in ability.