This study follows the successfully completed HOLOBalance project which was funded by the EU Horizon 2020 scheme. TheHOLOBalance platform delivers exercises demonstrated via a hologram of the physiotherapist and corrected in real time by the hologram prompts based on performance monitoring via sensors. Further information is available at: https://holobalance.eu/. HOLOBalance was developed as a comprehensive rehabilitation protocol for individualised remote (tele)rehabilitation balance physiotherapy programme. It includes different multisensory balance and gait exercises, physical activity and memory training and exergames (video games which are also exercises) to improve balance function in older adults. The system can thus assess and remotely monitor how users are performing the exercises.

This multisite randomised control trial (TeleRehab DSS, short for TeleRehabilitation Decision Support System) aims to (i) determine the system's safety, acceptability, and feasibility explore effectiveness of running such programme in comparison with the current standard care for middle-age/older adults with balance disorders/falls due to MCI, vestibular disorders, stroke or long Covid. This study also aims to (ii) assess if balance function, gait, cognitive function, balance confidence, and wellbeing can improve more compared to standard intervention and (iii) provide preliminary data for a definitive randomised controlled trial.

This study involves human participants, and each clinical site has applied for appropriate ethical approval.

This is an assessor-blinded (researchers assessing the participants will not know what study group participants will be in), randomised (participants will join different study groups randomly) controlled study. Participants will be randomised using an online platform to undergo a home-based exercise programmes, into either the intervention group (IG) or control group (CG). Participants will not be able to choose their preferred group and must be willing to participate in the assigned group.

All study participants will attend two sessions at UCL. The first assessment will be within one week prior to starting the programme, and the second will be within one week of completing the programme. Participants will be asked to complete a questionnaire set, walking/balance tests and a cognitive test.

Participants will receive telephone calls each week to monitor their progress. Participants will also receive remote program reviews at weeks 3, 6 and 9, from a member of the research team to assess and change exercises as required. Participants will be advised to contact the research team by email or by telephone during working hours if they have concerns or questions about their rehabilitation program or the TeleRehab DSS system. The research team will judge whether an additional home visit is required. If a patient does not complete their exercises for three consecutive days, a flag/warning will appear on the patients dashboard as a priority patient to follow up with, within 24 hours.

Intervention Group (IG): TeleRehab DSS The intervention (TeleRehaB DSS) group participants will be visited by a research team member to install the TeleRehab DSS system in their home and taught how to use the system, with a practice session. The system comprises a depth camera, lightweight augmented reality headset that displays the hologram, body-worn sensors that record movements and a heart rate sensor. Participants will be required to wear all the equipment when performing the prescribed exercises. A demo-video (including equipment and hologram) is available at www.holobalance.eu. Exercise progressions will be suggested by the AI-supported TeleRehaB DSS and approved by the clinicians at weeks 3, 6, and 9, which will be loaded into the participant's programme. At the end of the study, participants will be invited to take part in an interview to discuss their experience with using the TeleRehab DSS system.

The IG will receive the TeleRehaB DSS supported, prescribed, progressed and delivered intervention. In the TeleRehaB DSS IG, the platform will suggest two possible management strategies, on an individualized basis, based on patient profiles and expected benefit: 1)The high-tech, full TeleRehaB DSS with all components of the intervention consisting of TeleRehaB DSS AI-progressed multisensory balance exercises with the use of the AR avatar, real time feedback, AR gamified intervention, sensor monitored exercise performance and additional cognitive training, 2) the low-tech, basic version of TeleRehaB DSS, with depth camera, sensors and tablet - multisensory balance exercises, real time feedback, sensor monitored exercise performance and cognitive games, with no exergames, no smartwatch, and no mobile phone. The clinician can override the TeleRehab DSS group allocation decision if it is deemed unsafe. The intervention will be delivered as a daily (5 days per week, 12 weeks long) home-based exercise programme prescribed by non-experts (junior physiotherapist without vestibular expertise or non physio) with DSS support and coaching.

Control group (CG):

Control group participants will receive standard balance rehabilitation. Stroke and mild cognitive impairment (MCI) participants will receive the OTAGO home exercise program, while vestibular dysfunction and long covid-19 participants will receive the Meniere's Dizziness Booklet program.

1. OTAGO Home Exercise Programme (HEP), a balance exercise programme developed by a research group at University of Otago, New Zealand. The OTAGO HEP will be provided to all individuals in the control arm who report falls/are at risk of falls. The OTAGO group participants will receive a pamphlet with instructions for home exercises within the programme, resistance bands and an exercise diary. The OTAGO HEP booklet is available at https://www.livestronger.org.nz/assets/Uploads/acc1162-otago-exercise-manual.pdf
2. Vestibular rehabilitation programme - for participants with problems chronic (lasting >3 months) dizziness/imbalance due to chronic vestibular disorder (affecting the vestibular /balance system) or due to long Covid). The vestibular rehabilitation group participants will receive a booklet with vestibular exercises which have been individualised based on the assessment by the research team member. The exercise booklet is a validated and widely used intervention for vestibular disorder. This will be provided to all individuals in the control arm with chronic dizziness/imbalance (>3 months) without falls/risk of falls (FGA>22). The booklet has descriptions and diagrams of the exercises and instructions on how to progress these as well as an exercise log, available at: https://www.menieres.org.uk/files/pdfs/balance-retraining-2012.pdf

ALL PARTICIPANT Inclusion Criteria:

• Age 40-80 years
• community dwelling able to walk 500-m independently or with a stick
• Depression subscale on Hospital Anxiety and Depression Scale <10/21 (14-item questionnaire)
• No significant visual impairment (as self-reported by participants)
• Willing to comply with study procedures, proposed training and testing regime
• With capacity to consent
• No acute musculoskeletal or other injuries that would prevent participation in a structured exercise program
• Is not currently, and has not in the past 8-weeks received any falls/balance/vestibular and/or cognitive rehabilitation.
• Does not any implanted medical devices or a cardiac pacemaker.
• Does not have any other co-existing neurological conditions (ie. Multiple sclerosis, Parkinson's disease, neuropathy etc.)
• Does not have any language or communication deficits impairing their ability to communicate and/or express their thoughts.
• Has at least one functional hand for grip function and computer use.
• Fulfilling all of the criteria from one of the below sub-groups

STROKE COHORT who will fulfil the additional criteria:

• Individuals with diagnosis of focal ischaemic or haemorrhagic stroke, as confirmed by a clinical letter.
• Onset >/= 3 months prior to study.
• Montreal Cognitive Assessment (MoCA) score n >/=23
• At risk of falls (i.e. Functional Gait Assessment FGA score </=22/30; FGA is a validated quick balance task assessment) AND/OR having experienced a fall(s) in the last 12 months

MCI COHORT who will fulfil the additional criteria:

• Individuals with new or existing formal diagnosis of MCI, according to the International Classification of Disease 10 (ICD10) , as confirmed by a clinical letter.
• At risk of falls (FGA </= 22/30) AND/OR having experienced a fall(s) in the last 12 months.

VESTIBULAR COHORT who will fulfill the additional criteria

• Montreal Cognitive Assessment (MoCA) score n >/=23
• Individuals with a diagnosis of a vestibular disorder (peripheral and/or mixed peripheral and central):
• Peripheral vestibular disorder in which the balance problem lies in the vestibular/balance system within the inner ear.
• Mixed vestibular disorder in which the balance problem lies in the vestibular/balance system within the inner ear (peripheral) and involving the nerves or neuronal network in the brain/brainstem responsible for balance (central).
• Chronic dizziness and/or unsteadiness (>/= 3 months duration) that started at the time or after the vestibular disorder diagnosis.
• Dizziness handicap inventory (DHI >34) AND/OR At risk of falls (FGA </=22/30)

LONG COVID-19 COHORT who will fulfill the additional criteria:

• Montreal Cognitive Assessment (MoCA) score n >/=23
• Individuals with laboratory confirmed diagnosis of Covid (>/=6 months prior to study onset), as confirmed by a clinical letter.
• Who have been diagnosed with long Covid, as confirmed by a clinical letter.
• Who have chronic dizziness and/or unsteadiness which started after the Covid illness (self-report by the patient; duration </=3 months).
• Dizziness handicap inventory (DHI >34) AND/OR At risk of falls (FGA \

Anonymised data collected willl be analysed, and a Final Study Report prepared. with results published in academic journals and disseminated in relevant clinical/scientific peer-reviewed literature and conferences. No participant identifiable data will be included in the final study reports or in the process of dissemination of the study results. The participants will be guided to where they can access the final result publication(s). The study protocol and study report will be published. Anonymised data will be uploaded to the Zenodo data repository and will be available to other researchers in line with open science principles. The research data collected in the course of the study will be retained by UCL and other clinical partners in their capacity as a sponsor for 20 years after the research study has ended. The data will be then securely destroyed.

20 years after the research study has ended; Nov 2025 - Nov 2045

All study research team members at all clinical sites will comply with their local requirements with regards to the collection, storage, processing and disclosure of personal information and will uphold the Act's core principles.

The creation of coded, depersonalised data where the participant's identifying information will be replaced by an unrelated sequence of characters will be in place. The digital data collected will be stored in digital format at each clinical sites secure safe haven data platform with encrypted and password protection. The data (hard copies) collected during the study will be stored in the study site file in a securely locked designated cabinet at each clinical site for the duration of the study.

Outcome assessors will be blinded to which study arm participants have been allocated to. Due to the nature of the study, investigator's and participants cannot be blinded, althouhg intervention group participants will be blinded as to which intervention (High vs. Low tech) they have been allocated to.