Effect of exercise and brain stimulation on balance and walking in people at risk of falling: A feasibility study

Intervention: Participants will attend a rehabilitation exercise programme delivered in groups of 4-6 older adults by a physiotherapist twice a week for 8 weeks. An attendance record will be kept by the Physiotherapist running the programme. The exercise programme is a 50 minute, low intensity progressive programme based on standard principles of balance training focussing on the integration of the visual, vestibular and somatosensory systems. Types of exercises in the programme include; standing and walking on unstable surfaces, vestibular ocular habituation (head turning) exercises, and controlling limits of stability (standing with a progressively smaller base of support)- these will all be done at a Borg scale of exertion 11-12 (Exercises that require some exertion but not enough to speed up your breathing). The exercise session will conclude with 5-minutes static cycling at a Borg scale of perceived exertion of around 13 (Requiring moderate effort and speeds up your breathing but doesn’t make you out of breath). Treatment group participants will complete the exercise programme whilst receiving noisy Galvanic Stimulation (nGVS) for 45 minutes. Participants wear electrodes placed over the mastoid process by either the Physiotherapist or research assistant and attached to a commercially available galvanic stimulator (Softrex Medical). Staff will be trained in the application and use of the nGVS machines by a member of the research team experienced in their use. The nGVS machines are designed for research and will be programmed to the nGVS setting by an unblinded member of the research team and numbered with the participants study number. The nGVS is white noise GVS - a zero-mean random signal with equal intensities at different frequencies. The intensity is set at 0.5mA and is of imperceptable magnitude (the participant is unable to feel or hear the nGVS). Comparator/ Control group This study uses a 3-armed randomised double blinded, parallel, control trial design. There will be two groups that control for treatment effect, the sham group and the control group. The Sham Group will wear electrodes over the mastoid process applied by the Physiotherapist or Research assistant and attached to the galvanic stimulator which has been programmed to the sham setting by the unblinded researcher. As the nGVS is administered at a subsensory level neither the Therapist or participant will know whether they are receiving sham nGVS or nGVS. Sham group participants will partake in the same exercise programme as the treatment group participants. The Control Group will receive no intervention (nGVS or exercise programme) but will be offered the same balance rehabilitation programme as the treatment and sham group after the 6-month follow up assessment.