Age-related differences during a gaze reorientation task while standing or walking on a treadmill.

Falls among adults over the age of 65 years have become a growing concern. Two factors related to high incidence of falls in this group of adults are decreased head stability and impaired balance. Older adults' level of control of head stability or balance is unknown when they must reorient their gaze. In the current study, ten older adults (69 +/- 3.27 years) performed a gaze reorienting task while standing or walking on a treadmill. The task was the same as that used on young adults by Cinelli et al. (2007). The results show that older adults use a different strategy than young adults when reorienting gaze. Shoulder and hip rotations occurred synchronously when standing and were more variable when walking on a treadmill. As well, there was a larger difference between the onset of eye movements and body segment movement in the older adults. These differences can be accounted for by decreases in physiological subsystems. The visual presence of a visual target helped the older adults stabilize their heads-in-space by incorporating information from more than one sensory system.