There is a heightened use of prefrontal/executive control resources in older adults and post-stroke adults during walking. The level of prefrontal resource utilization, particularly during complex walking tasks like obstacle crossing, may approach the ceiling of available resources for people who have walking deficits. Prior cognitive research has revealed that prefrontal over-activation combined with limited prefrontal resources can lead to poor cognitive performance. The present study suggests a similar situation influences walking performance. Future research should further investigate the extent to which prefrontal over-activation during walking is linked to adverse mobility outcomes.

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Multisite pain, or pain that occurs simultaneously at >1 anatomical site, is more prevalent than single-site pain. While multisite pain affects over half of older adults, it remains an understudied pain entity that may have important functional implications in an aging population. Greater understanding of this complex pain entity from a biopsychosocial perspective is critical for optimizing clinical and functional outcomes in older adults with pain. Therefore, the primary purpose of this review is to summarize the relationship between multisite pain and functional outcomes in older adults to further elucidate the impact of multisite pain as a distinct entity within this population. A comprehensive literature search revealed 17 peer-reviewed articles. Multisite pain in older individuals is associated with reductions in several physical function domains: 1) lower-extremity mobility; 2) upper-extremity impairments; 3) balance and increased fall risk; and 4) general disability and poor physical function. Further, multisite pain in older individuals is associated with psychological dysfunction (eg, anxiety and depressive symptoms) and social factors (eg, income and education). Overall, this review highlights the scant literature investigating the functional implications of multisite pain in an aging population. Further, while multisite pain appears to have functional consequences, the neurobiological mechanisms contributing to this relationship are unknown. Thus, how this pain characteristic may contribute to the variability in pain-related functional outcomes among older adults is not clear. Future investigations are strongly warranted to advance the understanding of multisite pain and its broad impact on physical and psychosocial function in older adults.

Background : Functional near-infrared spectroscopy (fNIRS) is a valuable neuroimaging approach for studying cortical contributions to walking function. Recruitment of prefrontal cortex during walking has been a particular area of focus in the literature. The present study investigated whether task-related change in prefrontal recruitment measured by fNIRS is affected by individual differences in people post-stroke. The primary hypotheses were that poor mobility function would contribute to prefrontal over-recruitment during typical walking, and that poor cognitive function would contribute to a ceiling in prefrontal recruitment during dual-task walking (i.e., walking with a cognitive task). Methods : Thirty-three adults with chronic post-stroke hemiparesis performed three tasks: typical walking at preferred speed ( Walk ), serial-7 subtraction ( Serial7 ), and walking combined with serial-7 subtraction ( Dual-Task ). Prefrontal recruitment was measured with fNIRS and quantified as the change in oxygenated hemoglobin concentration (ΔO 2 Hb) between resting and active periods for each task. Spatiotemporal gait parameters were measured on an electronic walkway. Stepwise regression was used to assess how prefrontal recruitment was affected by individual differences including age, sex, stroke region, injured hemisphere, stroke chronicity, 10-meter walking speed, balance confidence measured by Activities-specific Balance Confidence (ABC) Scale, sensorimotor impairment measured by Fugl-Meyer Assessment, and cognitive function measured by Mini-Mental State Examination (MMSE). Results : For Walk , poor balance confidence (ABC Scale score) significantly predicted greater prefrontal recruitment (ΔO 2 Hb; R 2 = 0.25, p = 0.003). For Dual-Task , poor cognitive function (MMSE score) significantly predicted lower prefrontal recruitment (ΔO 2 Hb; R 2 = 0.25, p = 0.002). Conclusions : Poor mobility function predicted higher prefrontal recruitment during typical walking, consistent with compensatory over-recruitment. Poor cognitive function predicted lower prefrontal recruitment during dual-task walking, consistent with a recruitment ceiling effect. These findings indicate that interpretation of prefrontal recruitment should carefully consider the characteristics of the person and demands of the task.