A Systematic Review of the Effects of Interactive Telerehabilitation with Remote Monitoring and Guidance on Balance and Gait Performance in Older Adults and Individuals with Neurological Conditions

Recognizing the growing interests and benefits of technology-assisted interactive telerehabilitation in various populations, the aim of this review is to systematically review the effects of interactive telerehabilitation with remote monitoring and guidance for improving balance and gait performance in older adults and individuals with neurological conditions. The study protocol for this systematic review was registered with the international prospective register of systematic reviews (PROSPERO) with the unique identifier CRD42024509646. Studies written in English published from January 2014 to February 2024 in Web of Science, Pubmed, Scopus, and Google Scholar were examined. Of the 247 identified, 17 were selected after initial and eligibility screening, and their methodological quality was assessed with the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-sectional Studies. All 17 studies demonstrated balance and gait performance improvement in older adults and in individuals with stroke, Parkinson’s disease, and multiple sclerosis following 4 or more weeks of interactive telerehabilitation via virtual reality, smartphone or tablet apps, or videoconferencing. The findings of this systematic review can inform the future design and implementation of interactive telerehabilitation technology and improve balance and gait training exercise regimens for older adults and individuals with neurological conditions.


Introduction
Across all age groups, maintaining stable balance and gait ensures mobility, movement coordination, and overall well-being [1].Balance and gait impairments affect daily activities and quality of life, particularly by increasing the risk of falling and actual falls [2].Indeed, falls are one of the most significant global health concerns, which can result in fractures, concussions, and even death [3].Individuals with balance impairments often need balance rehabilitation to improve stability, reduce fall risk, and increase overall functional independence [4].
Systematic reviews of conventional balance rehabilitation regimens have documented balance and gait performance improvement in older adults [5] and individuals with stroke [6], Parkinson's disease [7], traumatic brain injury [8], and multiple sclerosis [9].Conventional balance rehabilitation regimens, however, often limit or prevent an individual's full participation due to the unavailability of physical therapists, limited access to clinical facilities, reduced accountability, and cost [10][11][12].Over time, an individual's compliance and motivation may decrease in the absence of feedback [13] or having to perform the same exercise regimen [14].
Bioengineering 2024, 11, 460 2 of 18 Some studies have documented the recent effects of developing and accessing various telerehabilitation technology to improve balance and gait performance in different populations [15][16][17], such as virtual reality (VR), video games that use RGB-D cameras (e.g., Kinect), instrumented boards (e.g., Wii Balance Board), and motion sensors (e.g., inertial measurement units).These studies have concluded that VR or game-based telerehabilitation provides benefits including improved accessibility for individuals facing geographical barriers or with no transportation to traditional rehabilitation facilities; exercises tailored to individual needs and abilities; real-time feedback; more variety in exercise regimens; and increased exercise consistency.
Although two reviews have summarized the beneficial effects of videoconferencing interventions on telerehabilitation in older adults with musculoskeletal conditions [18] and individuals with stroke [19], there is no systematic review of the effects of telerehabilitation with remote monitoring and guidance to improve balance and gait performance in different populations.Indeed, remote monitoring and guidance allow for ongoing assessment, immediate feedback, adjustment of exercise intensity, timely interventions, and improved relationships between users and healthcare professionals, which can enhance the overall efficacy and success of the telerehabilitation program.Therefore, the aim of this review is to systematically review the effects of remote monitoring and guidance on telerehabilitation using VR, game-based systems, smartphone apps, and web-based videoconferencing for improving balance and gait performance in older adults and individuals with neurological conditions.This systematic review, in particular, includes studies that focus on the effects of interactive telerehabilitation on balance and gait performance in older adults and people with stroke, Parkinson's disease, or multiple sclerosis, as well as the efficacy of interactive telerehabilitation over conventional rehabilitation (i.e., usual care, in-clinic, in-person, or in-home regimens).

Search Strategy
This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria and guidelines [20].Both authors determined appropriate databases, identified keywords, specified search terms, and developed the protocol for this systematic review.The Web of Science, PubMed, and SCOPUS databases and the Google Scholar search engine were used to search published articles.The search keywords, which was modified as needed, included all possible combinations of "telerehabilitation"; "telerehabilitation training"; "interactive telerehabilitation"; "balance"; "gait"; "remote*"; "bidirectional*"; "monitoring"; "guidance"; "older adults"; "stroke"; "Parkinson's disease"; and "multiple sclerosis".Manual searches of the reference lists used in previous systematic reviews of conventional balance and gait rehabilitation were also conducted.Searches were limited to data published between January 2014 and February 2024.Systematic, perspective, and narrative reviews, survey articles, and books and book chapters were excluded.The study protocol was registered with the international prospective register of systematic reviews (PROSPERO) with the unique identifier CRD42024509646.

Study Selection
Both authors independently selected potential studies, and they then discussed and resolved any discrepancies through in-depth discussion and mutual agreement to determine the studies included in this systematic review.Figure 1 shows the flow diagram for study selection according to PRISMA criteria and guidelines.Studies were included if they were published in English, peer-reviewed, and full-text accessible; provided balance-related telerehabilitation exercises with remote monitoring or guidance (i.e., interactive telerehabilitation); provided remote interventions or remote tracking of progress; used technologies including VR or game-based systems, smartphone apps, or web-based videoconferencing; and included individuals with balance impairments (i.e., older adults and people with stroke, Parkinson's disease, or multiple sclerosis).Studies were excluded if they developed telerehabilitation technology only; evaluated telerehabilitation technology used in laboratory settings; developed experimental protocols; used fewer than 10 individuals to evaluate the feasibility and usability of telerehabilitation technology or telerehabilitation protocols with less than 10 individuals; used telerehabilitation without remote monitoring or guidance (i.e., non-interactive telerehabilitation); used hybrid telerehabilitation protocols (i.e., a combination of in-person and in-home rehabilitation); used balance-related exercises without telerehabilitation; used no objective outcome measures for evaluating balance and/or gait performance after telerehabilitation; and included no individuals with balance impairments caused by age, diseases, or clinical conditions (i.e., older adults and people with stroke, Parkinson's disease, or multiple sclerosis).

Data Extraction and Tabulation
After determining the studies included in this systematic review, both authors extracted information and data.Furthermore, both authors comprehensively examined and discussed methodologies for statistical analysis, descriptive statistics, and significant outcome measures in each study to minimize the potential confounding of the results.
The information and data included the following: author(s); publication date; participant characteristics; sample size; balance and/or gait telerehabilitation intervention; remote monitoring and/or guidance method; exercise frequency and total duration of intervention; assessment period; and objective and/or clinical outcome assessments of balance and/or gait rehabilitation.

Methodological Quality
The methodological quality was assessed with the National Institute of Health's Quality Assessment Tool for Observational Cohort and Cross-sectional Studies [21].The tool assesses the responses "Yes", "No", and "Other" ("Cannot Determine", "Not Reported", "Not Available") to 14 questions.Each author of this systematic review independently assessed the methodological quality of the 17 studies included.After the authors' assessment and in-depth discussions, each study was classified into "good", "fair", or "low" methodological quality [21]."Good quality" received "Yes" responses to 8 or more of the 14 questions; "fair quality" received "Yes" responses to 5, 6, or 7 questions; and "low quality" received less than 5 "Yes" responses [22].

Literature Search
Figure 1 shows the sequential process for study selection according to PRISMA guidelines.An initial database search identified 247 studies, of which 155 were removed for duplicate records, review articles (i.e., systematic, perspective, and narrative reviews), survey articles, books and book chapters, non-English articles, and inaccessible articles.Of the 92 remaining studies, 35 were removed after title and abstract screening, and of the remaining 57, 40 were removed after full-text screening because they were not telerehabilitation or in-home training (n = 30); were hybrid training (i.e., in-person and in-home rehabilitation) (n = 1); did not provide balance or gait exercises (e.g., cardiovascular exercise) (n = 5); had no balance-and gait-related outcome measures (n = 2); and did not use individuals with balance impairments caused by age, diseases, or clinical conditions.The final number was 17 studies.

Quality Assessment
Table 2 reports the results of the methodological quality assessment; no studies were excluded based on the results of the assessment.Since all 17 studies had objective measures, the Q12 was not applicable (N/A) and was excluded from the methodological quality assessment.All 17 studies received "Yes" responses to 12 or more of the 14 questions and were rated as good overall quality with a low risk of bias.Of the 17, 10 studies did not provide a justification or perform a power analysis for their sample sizes.Note: Q1: Was the research question or objective in this paper clearly stated?; Q2: Was the study population specified and defined?; Q3: Was the participation rate of eligible persons at least 50%?; Q4: Were all the subjects selected or recruited from the same or similar populations (including the same time period) and were inclusion and exclusion criteria for being in the study prespecified and applied uniformly to all participants?;Q5: Was a sample size justification, power description, or variance and effect estimates provided?;Q6: For the analyses in this paper, were the exposure(s) of interest measured prior to the outcome(s) being measured?;Q7: Was the timeframe sufficient so that one could reasonably expect to see an association between exposure and outcome if it existed?; Q8: For exposures that can vary in amount or level, did the study examine different levels of the exposure as related to the outcome (e.g., categories of exposure, or exposure measured as continuous variable)?;Q9: Were the exposure measures (independent variables) clearly defined, valid, reliable, and implemented consistently across all study participants?;Q10: Was the exposure(s) assessed more than once over time?; Q11: Were the outcome measures (de-pendent variables) clearly defined, valid, reliable, and implemented consistently across all study participants?;Q12: Were the outcome assessors blinded to the exposure status of participants?; Q13: Was loss to follow-up after baseline 20% or less?; and Q14: Were key potential confounding variables measured and adjusted statistically for their impact on the relationship between exposure(s) and outcome(s)?

Discussion
This systematic review selected 17 studies to assess the effects of interactive telerehabilitation (VR, smartphone-and tablet-based learning apps, gamification, videoconferencing) with remote monitoring and guidance on balance and gait performance in different populations.All 17 studies included in this review demonstrated the beneficial effects of telerehabilitation for improving balance and/or gait performance in older adults, individuals with stroke, individuals with Parkinson's disease, and individuals with multiple sclerosis.The following sub-sections discuss the contributions of the interactive telerehabilitation technologies; remote monitoring and guidance methods; and improvements in balance and gait performance for different populations.The discussion ends with the limitations of this systematic review.

Interactive Telerehabilitation Technologies
The target populations in all 14 studies were under care at home and performed long-term (4 weeks or longer) balance and gait training in their domestic settings (i.e., in home or in home and around home).Smartphone-based and tablet-based telerehabilitation technology particularly benefited individuals with mobility limitations and individuals living far from physical therapy facilities and clinics.The target populations used remote telerehabilitation technology to schedule their training, which allowed them to schedule sessions at their preferred time and exempted the healthcare facilities from scheduling the appointment.Potentially, telerehabilitation technology could reduce the cost of healthcare as well as the burden on healthcare facilities [40,41].
Integrating VR, smartphone-or tablet-based apps, gamification, and videoconferencing into interactive telerehabilitation can improve overall accessibility, personalization, engagement, real-time monitoring and guidance, cost-effectiveness, and data-driven decision-making.Receiving sensory biofeedback while performing motor tasks can improve the individual's acquisition of task skills and support the repetitive exercises [44][45][46].Receiving sensory biofeedback while performing motor tasks can improve an individual's acquisition of task skills and support the repetitive exercising [44][45][46].

Remote Monitoring and Guidance Methods
Remote monitoring and guidance through telecommunication technologies have increasingly been recognized as a viable approach to improve individualized care, facilitate timely intervention, empower individuals, and encourage self-management [18,19].Several techniques have been employed for remote monitoring and guidance in telerehabilitation, including secure messaging and calling, mobile apps, videoconferencing, and healthcare platforms.
Among the 17 studies included in this review, videoconferencing was the most common method (n = 12).This can be primarily attributed to its relative affordability, availability, ease of use, and user-friendly freeware or commercial videoconferencing software.Of the 17 studies, 12 used videoconferencing software to administer, monitor, and supervise telerehabilitation exercises in real-time [27,28,[31][32][33][34][35]37], or after the completion of exercises [25,26,30,39], and the remaining 5 used either secure messaging [23,24], phone calls [29,36], or a healthcare platform [39].All 12 studies found that therapists or instructors supervised and monitored exercise progress; demonstrated proper exercise techniques and movements; visually assessed, guided, and adjusted body movements; adjusted exercise intensity, duration, and type; and supported and encouraged individuals during exercise regimens.

Limitations
The systematic review had the following limitations.First, publication bias may be present because only interactive telerehabilitation via remote monitoring and guidance described in published studies are considered.Second, using the keywords "telerehabilitation", "remote*" or "bidirectional*" and "monitoring" or "guidance" may overlook studies published under different titles or keywords.Third, limiting the review to specific populations may prohibit generalizing the results to other populations.Fourth, using the outcome measures of balance and/or gait performance does not capture the effects of interactive telerehabilitation for cognitive, social, general well-being, and other aspects.Fifth, a language bias may be present, because only English language publications are considered.Sixth, the review cannot quantitatively compare the outcomes of the 17 studies, because of heterogeneity (i.e., demographic characteristics, telerehabilitation technology, research design, interventions, and outcome measures).Seventh, the review cannot formulate evidence-based recommendations due to the lack of a method for evaluating the quality of evidence (e.g., Grading of Recommendations Assessment, Development, and Evaluation (GRADE) [47]).Eighth, limiting the review to studies undertaken in high-income countries may prohibit generalizing the results to lower-and middle-income countries.

Conclusions
The systematic review found strong evidence of the beneficial effects of interactive telerehabilitation via remote monitoring and guidance for balance and gait exercise regimens.The treatment outcomes of older adults and individuals with neurological conditions (i.e., stroke, Parkinson's disease, and multiple sclerosis) were better than, or as good as, conventional in-clinic and in-home rehabilitation.The findings indicate that interactive telerehabilitation is likely to replace conventional rehabilitation methods for older adults, individuals with neurological conditions, and balance-and gait-impaired individuals of any age who cannot travel.Advances in interactive telerehabilitation technology may also promote the use of remote monitoring and guidance in a changing climate.
The results of the review suggest the following research pursuits.Integrating artificial intelligence and machine learning into telerehabilitation technology could enhance personalization and remote interventions.The findings obtained from a widespread investigation of telerehabilitation platforms by healthcare professionals, caregivers, and target populations could improve future usability, user satisfaction, and acceptance.The costeffectiveness and economic benefits (i.e., potential savings in healthcare resources; improvements in healthcare delivery) of telerehabilitation versus traditional rehabilitation need a comprehensive assessment.Analysis of interactive telerehabilitation implementations and secure communications infrastructure could identify the range of factors influencing the scalability and sustainability of remote interventions.An assessment of the influence of communication infrastructure on the provision and accessibility of telerehabilitation services is necessary.A study of interprofessional collaboration could reveal new methods of teamwork for healthcare professionals who provide remote monitoring and guidance and for those who provide care and assistance in the home.

Bioengineering 2023 ,
10, x FOR PEER REVIEW 3 of 18 related telerehabilitation exercises with remote monitoring or guidance (i.e., interactive telerehabilitation); provided remote interventions or remote tracking of progress; used technologies including VR or game-based systems, smartphone apps, or web-based videoconferencing; and included individuals with balance impairments (i.e., older adults and people with stroke, Parkinson's disease, or multiple sclerosis).

Figure 1 .
Figure 1.The PRISMA flow diagram illustrates the sequential process by which studies were identified, screened, assessed, and included in this review.

Figure 1 .
Figure 1.The PRISMA flow diagram illustrates the sequential process by which studies were identified, screened, assessed, and included in this review.

Table 1 .
Participant characteristics, intervention and training methods, details of technologies, assessment periods, and summary of outcome measures.

Table 1 .
Cont.Meyer Assessment-Lower Extremity; MDS-UPDRS III: Movement Disorders Society Unified Parkinson Disease Rating Scale section for motor impairment; Mini-BESTest28: Mini Balance Evaluations Systems Test (a total score of 28 points); Mini-BESTest32: Mini Balance Evaluations Systems Test (a total score of 32 points); mRS: Modified Rankin scale; NHPT: Nine-Hole Pegboard Test; POMA-B: Performance-Oriented Mobility Assessment balance subscale; POMA-G Performance-Oriented Mobility Assessment gait subscale; S-PASS: Spanish version of Postural Assessment Scale for Stroke Patients; S-TIS 2.0: Spanish version of the Trunk Impairment Scale 2.0; SOT: Sensory Organization Tests; SPPB: Short Physical Performance Battery; TUG: Timed Up-and-Go; TUG-D: Timed Up-and-Go-test Dual-task; UPDRS: Unified Parkinson's Disease Rating Scale; and VR: Virtual Reality.

Table 2 .
Results of the methodological quality assessment.