Table 1 –

Article Inclusion and Exclusion Criteria

Inclusion Criteria	Exclusion Criteria
• Studies were included if they reported cortical activity during a walking or balance task (such as; walking, turning, obstacle crossing, standing, standing with perturbation etc.).	• Articles were excluded if they involved simple motor tasks (i.e. button pressing, finger tapping/movement, wrist/elbow extension or flexion, a single step) as these were not considered to be walking or balance tasks.
• Whereby articles included another clinical cohort (e.g. multiple Sclerosis) or a static imaging task, only data pertaining to older adult or PD participants during a walking or balance task was reviewed.	• Only articles written in English were considered and abstracts, case studies, reviews, commentaries, discussion papers, editorials or conference proceedings were excluded.
	• Experiments that involved assays of walking or balance (e.g. motor imagery or virtual reality) without task performance, or that involved pre and post-task cortical measurement rather than during task recording were also excluded, as these may not represent activity that actually occurs during the task.
	• Articles related to animal models (monkey, rat or mouse) were excluded with separate key terms.