Feasibility of Home-based tES for Older Adults at Risk of Falling

In this project, the investigators propose to demonstrate the feasibility of remotely-monitored, caregiver (or spouse)-administered, home-based tES (transcranial electrical stimulation) intervention to improve mobility in ambulatory older adults with recent falls. This is a four-phase feasibility study in older, ambulatory adult participants at risk of falling due to a loss of balance (participant faller, PF) together with a willing and able participant administrator (PA) that is available during weekdays to administer tES to the PF. Phase 1 is focused on the development and refinement of our training materials for home-based tDCS (transcranial direct current stimulation) for PF/PA pairs. The objectives of this phase: 1. Identify areas of confusion and challenges for older adults. 2. Refine our training materials to accompany the home-based tDCS system. In Phase 2, the investigators will complete a pilot trial in 12 PF/PA pairs to assess the feasibility of deploying home-based tES in larger clinical trials, and to prepare for the development and implementation of such trials. The objectives of this phase: 1. Determine the mean/range number of visits needed for in-person training. 2. Compliance and retention with the study protocol. 3. Safety/side effects of home-based tES, as compared to previously established laboratory-based tES data. The investigators hypothesize that adult PAs are able to successfully administer home-based tES to PFs. The investigators also expect that PF/PA pairs will exhibit excellent adherence to the intervention and that the prevalence and severity of reported tDCS side-effects will be similar to that observed in previous laboratory-based studies. In Phase 3, the investigators will complete a pilot trial in up to 18 PF/PA pairs; i.e., those who have previously successfully completed either Phase 1 or Phase 2. The study objectives/aims for Phase 3 are: 1. Further explore compliance and retention with the study protocol over a longer ti