 Although walking has long been considered as primarily an automatic motor task, emerging evidence suggests that this view may be overly simplistic. Cognitive function may play a key role in the regulation of even routine walking, particularly in older adults. Attention is a necessary cognitive resource for maintaining normal walking and there is evidence that cognitive and attentional deficits are independently associated with postural instability, impairment in performing daily living activities, and future falls. The role of cognition in walking is even more marked in people with cognitive dysfunction, whose gait performance is affected by any extra cognitive load. A sensitive way to quantify gait performance is by assessing the gait variability. Gait variability is defined as the stride-to-stride variation in time, and quantifies the automaticity of gait, with greater variability indicating less rhythmicity and a more unstable gait pattern. Evaluating gait variability offers an accurate methodology to identify subtle changes on walking because of pathological conditions or disease. For instance, cognitively normal older adults have low gait variability; however, high gait variability has been described in Parkinsons disease, Alzheimer disease, and has been associated with high risk of future falls and mobility decline. Additionally, previous studies have demonstrated that gait variability may serve as a clinically relevant parameter in the evaluation of mobility, and may be a responsive measure for different interventions in fall prevention. 