Cognitive impairment has been considered to be a negative prognostic factor for successful rehabilitation and functional recovery [38]. Lower scores on the MMSE have also been associated with poorer physical performance on tests of gait speed, chair stand, and maximal inspiratory pressure and predicted 2 yr declines in physical performance on a summary measure of gait
speed, chair stand, and standing balance tests [33]. Successful execution of a physical task demands cognitive processes regardless of the nature of the task. Researchers using performancebased measures of physical functioning should pay particular attention to the cognitive
capacities of their subjects because these might influence