Effect and immediate after-effect of lightly gripping the cane on postural sway

BACKGROUND: This study investigated the effect and after-effect of lightly touching a real cane on postural sway and ankle muscle activity. METHOD: Participants performed a single-leg stance (SLS) task with their eyes closed for 30 s under three tasks. In the first and third tasks, the participants performed a normal SLS. In the second task, the participants in light-grip group (n = 11) were asked to perform SLS while lightly gripping a cane with their hand. The participants in depend-on-cane group (n = 11) were asked to support their own body with a cane. RESULTS: Postural sway during a single-leg stance is decreased by light gripping and is accompanied by decreased co-contraction of the ankle-joint muscles. If a participant lightly gripped a cane, postural sway decreased not only during the light gripping but also immediately after the withdrawal of the cane. Although postural sway and co-contraction in the depend-on-cane group were significantly decreased during the second task compared to the first task, they were not significantly changed between the first and third tasks. CONCLUSION: These results suggest that lightly gripped cane provides a haptic sensory cue that can be used to assist postural control mechanisms due to enhanced perception of self-motion through sensory interaction with the environment through the cane. Further, the haptic sensory cue during postural maintenance might be promoted as a practice effect of postural control.