Applying Game-Based Approaches for Physical Rehabilitation of Poststroke Patients: A Systematic Review

Objective A large number of patients need critical physical rehabilitation after the stroke. This study aimed to review and report the result of published studies, in which newly emerged games were employed for physical rehabilitating in poststroke patients. Materials and Methods This systematic review study was performed based on the PRISMA method. A comprehensive search of PubMed, Scopus, IEEE Xplore Digital Library, and ISI Web of Science was conducted from January 1, 2014, to November 9, 2020, to identify related articles. Studies have been entered in this review based on inclusion and exclusion criteria, in which new games have been used for physical rehabilitation. Results Of the 1326 retrieved studies, 60 of them met our inclusion criteria. Virtual reality-oriented games were the most popular type of physical rehabilitation approach for poststroke patients. “The Nintendo Wii Fit” game was used more than other games. The reviewed games were mostly operated to balance training and limb mobilization. Based on the evaluation results of the utilized games, only in three studies, applied games were not effective. In other studies, games had effective outcomes for target body members. Conclusions The results indicate that modern games are efficient in poststroke patients' physical rehabilitation and can be used alongside conventional methods.


Introduction
Stroke is one of the diseases that can lead to disability and affect people's daily activities and lead to reduced performance [1]. According to the Global Burden of Diseases (GBD 2010), stroke is the second most common cause of death worldwide [2]. In 2010, the number of people with the first stroke was 16.9 million, and people who died of stroke was 5.9 million [2]. Disability-adjusted life years (DALYs) lost also was 102 million, and the number of stroke survivors was 33 million [2]. Ninety percent of stroke survivors have a disability in one of their functions [3]. Most people with poststroke disability experience changes in emotional function, limb movement, balance, and muscle strength, and there is a risk of falling for these patients in performing ordinary activities, all of which affect the quality of life of survivors [4].
e main treatment solution to reduce functional defects after stroke is rehabilitation [5]. Poststroke physical rehabilitation in common is a gradual process that can take months or even years, and these patients require multiple sessions of treatment. However, patients may not be able to attend these treatment sessions for rehabilitation fully. Several factors may lead to limited access to these treatment sessions, including the following: difficulty accessing a physiotherapist by the patient, high cost of attending the treatment session, patient's age and disability, the long distance that the patient has to travel, or poor patient compliance [6]. One of the solutions that can be offered to overcome these problems is to do rehabilitation activities at home; for rehabilitation exercises to be effective at home, high-intensity methods focused on specific repetitions of the practice with the feedback of performance should be used [7]. Consequently, one of the innovative methods that can obviate the above problems is applying modern games; these games have been used in various fields, including education, public policy, and healthcare [8]. Furthermore, they can also be utilized as a support tool for rehabilitation activities and provide an enjoyable environment for patients and increase adherence to treatment sessions [9,10].
As it turns out, various studies have been performed to determine the effectiveness of the mentioned games. A systematic review study by Primack et al. found that games improved 69% of psychological therapy outcomes, 46% of clinician skills outcomes, 42% of health education outcomes, and 37% of disease self-management outcomes [11]. Another study examined the games managed for rehabilitation in respiratory conditions and concluded these games were effective [12,13]. e purpose of this study is reviewing, summarizing, and reporting studies in which modern games have been used for physical rehabilitation of poststroke patients and tries to answer the following questions: (1) Which type of games is the most used? (2) Which gamification approaches have been used to improve the performance of poststroke patients? (3) What was the most common type of physical rehabilitation in stroke survivors? (4) What are the evaluation results of games used in poststroke patients?

Research Methodology
is systematic review was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analyzes (PRISMA) checklist to ensure inclusion of relevant studies [14].

Design.
In this review, a systematic search of scientific databases including ISI Web of Science, PubMed, IEEE Xplore Digital Library, and Scopus was performed from January 1, 2014, to November 9, 2020. e comprehensive search strategy comprised a set of main keywords from PubMed Mesh terms and Emtree related to "game," "rehabilitation," and "poststroke" patients. e specific detail of main applied keywords for each database is presented in Table 1.

Inclusion and Exclusion Criteria for Study Selection.
e extracted studies were included if they fulfilled the following criteria: (1) original articles and proceedings, (2) the focus of this review was on only physical rehabilitation innovative game-based solutions for poststroke physical disabilities, (3) one of the gamification techniques was employed for physical rehabilitation or disability treatment, (4) in this study, the result of using different games and outcomes of video games or immersive-oriented approaches on physical rehabilitation were reviewed, and (5) studies were limited to those published in the English language. Besides, the studies were excluded if they met the following criteria: (1) the title, abstract, or full text of the article that did not relate to video games, virtual, or mixed reality-based games, (2) studies which were review or meta-analysis, book chapters, letter, reports, and technical reports, (3) articles in which the result of applying games was not reported quantitatively, (4) articles about cognitive rehabilitation, and (4) non-English published ones.

Literature Refinement.
In comprehensive and scientific databases searching, 833 studies were retrieved after duplicate removal. Some inclusion and exclusion criteria were set for the study selecting phase. In the first phase, two independent reviewers (SS and SR) specified the primary classification of included studies; then, they synthesized selected citations' critical features. MG validated the primarily determined classifications. All titles and abstracts of extracted studies were investigated and screened based on the research questions and unique aims to select relevant ones by two reviewers under MG's supervision. In the last phase, citations that met inclusion and exclusion criteria were selected to enter the full-text review phase. e fulltexts of relevant studies were screened by SS and SR thoroughly. Key characteristics were entered into a spreadsheet in Excel for each study. Two authors (SR and SS) independently extracted the study characteristics based on the predefined classifications. For reaching an agreement, the information was examined again by two authors. e next reviewer (MG) evaluated and validated all of the obtained results. EndNote X9 was used for resource management, and all qualitative analyses were performed in SPSS v20. e main classifications of screened citations are shown in Figure 1.

Results
e flow of screening articles based on the PRISMA method is shown in Figure 2. Prior scientific searches assigned 833 citations after the duplicate removal phase. Next, 41 studies were eliminated due to their irrelevancy in the full-text screening phase. In the last screening step, 60 studies were included based on our main study objectives as eligible studies. Based on the predefined classification elements, a summary of the key results is described in Table 2.

Study Characteristics.
e reviewed studies in this study were published in 53 journals and 7 international conferences. All the names of journals and conferences are listed in Table 3 based on their frequency. As it is clear, the "Archives of Physical Medicine and Rehabilitation," "Clinical Rehabilitation," "Games for Health Journal: Research, Development, and Clinical Applications," and "Journal of Stroke and Cerebrovascular Diseases" have the first rank with 5 or 4 published studies among journals. e distribution of studies by year and country of publication is presented in Table 4. As it is conducted, the majority of citations were published in 2019. Accordingly, in different countries, innovative physical rehabilitation solutions were employed and Korea with 13 citations had the highest number of studies.

e Distribution of Literature by Main Gamification
Types and Approaches. Based on analysis, virtual reality-oriented games and video games are the most popular physical rehabilitation types for poststroke patients. e distribution of reviewed literature based on the type of games is shown in Figure 3. Besides, it turns out "Microsoft Xbox 360 Kinect" and "the Nintendo Wii Fit" approaches have been the widest utilized game-based tools that have been extracted in studies ( Figure 4). e deployment platform for most of the studies included in this review (n � 28, 46.66%) was Nintendo and Microsoft Xbox 360 Kinect.
ere are many games in the field of rehabilitation that researchers and therapists can use for rehabilitating patients. However, in this systematic review, most studies have used existing games in rehabilitation and do not develop games for the purpose of research that we can refer to the Nintendo Wii Fit, Microsoft Xbox 360 Kinect games, Peggle, IREX, and HTC Vive games.

Distribution of Studies Based on Type of Physical
Rehabilitation.
e critical types of physical rehabilitation therapies applied for poststroke patients based on different games were divided into several main categories. e most important types of rehabilitation are "Balance training," "Mobilization of the limbs," and "Muscular strengthening" ( Figure 5).

Distribution of Studies Based on Type of Studies, Sample
Size, and Session Detail. In the investigated studies, three types of intervention studies and their effectiveness have been utilized (Table 5). e sample size from minimum to maximum number is 5 people in 2 studies and 209 people in one study. e highest frequency for the selected sample size was 10 people, which is in 4 studies. e lowest age of the recruited subjects in studies was 24 years on average, and the highest mean of age was 72 years old. In most studies, the number of males included in the intervention was higher than females; in 4 studies, the exact number of genders was not reported.   OR "cerebrovascular accident" OR "cerebrovascular accidents" OR "CVA" OR "CVAs" OR "cerebrovascular apoplexy" OR "brain vascular accident" OR "brain vascular accidents" OR "cerebrovascular stroke" OR "cerebrovascular strokes" OR "apoplexy" OR "cerebral stroke" OR "cerebral strokes" OR "acute stroke" OR "acute strokes" OR "acute cerebrovascular accident" OR "acute cerebrovascular accidents") AND ("video games"[Mesh] OR "game" OR "games" OR "gamification" OR "video game" OR "computer games" OR "computer game") AND ("rehabilitation" [Mesh] OR "rehabilitation care") limit to: 2014-2020 Scopus TITLE-ABS-KEY (( "stroke" OR "cerebrovascular accident" OR "cerebrovascular accidents" OR "CVA" OR "CVAs" OR "cerebrovascular apoplexy" OR "brain vascular accident" OR "brain vascular accidents" OR "cerebrovascular stroke" OR "cerebrovascular strokes" OR "apoplexy" OR "cerebral stroke" OR "cerebral strokes" OR "acute stroke" OR "acute strokes" OR "acute cerebrovascular accident" OR "acute cerebrovascular accidents") AND ("video games" OR "game" OR "games" OR "gamification" OR "video game" OR "computer games" OR "computer game") AND ("rehabilitation" OR "rehabilitation care")) AND (limit to (pubyear, 2014-2021)) AND (limit to (doctype, "cp") OR limit to (doctype, "ar") AND (limit to (language, "English")) Web of Science TS � ("Stroke" OR "cerebrovascular accident" OR "cerebrovascular accidents" OR "CVA" OR "CVAs" OR "cerebrovascular apoplexy" OR "brain vascular accident" OR "brain vascular accidents" OR "cerebrovascular stroke" OR "cerebrovascular strokes" OR "apoplexy" OR "cerebral stroke" OR "cerebral strokes" OR "acute stroke" OR "acute strokes" OR "acute cerebrovascular accident" OR "acute cerebrovascular accidents") AND TS � ("video games" OR "game" OR "games" OR "gamification" OR "video game" OR "computer games" OR "computer game") AND TS � ("rehabilitation" OR "rehabilitation care") Refined by: document types: (article OR proceedings paper) Timespan: 2014-2020. Indexes: SCI-EXPANDED, SSCI, A&HCI, ESCI.

IEEE Library
(((((("All metadata" : "stroke") OR "all metadata" : "cerebrovascular accident") OR "all metadata" : "cerebral strokes") AND "all metadata" : "game") OR "all metadata" : "computer game") AND "all metadata" : "rehabilitation"). Filters applied: 2014-2021 e frequency of physical rehabilitation time (by unit time) is shown in Figure 6. In this study, the length of rehabilitation time is converted to hour to compare the treatment time in different studies. In studies, the minimum duration of treatment to provide rehabilitation is one hour; besides, 10, 9, and 12 hours is the highest frequency of treatment time in studies, which was intended in a total of 12 studies.

Distribution of Studies Based on Assessment Scores.
According to the results of reviewed different studies, numerous indicators and tests have been applied to evaluate physical rehabilitation outcomes in poststroke patients. In other words, according to the type of rehabilitation treatment provided to patients, different indicators and metrics have been calculated to assess the condition of the rehabilitated organs of the body (before and after the intervention). For this reason, we were unable to compare the assessment scores calculated during the intervention.
However, considering how many indicators and metrics in each study were affected by physical rehabilitation during the intervention treatment, we added a brief assessment from the authors' perspective. At the end of the intervention, if all indicators of functional or physical appraisal of patients are affected by game-based rehabilitation and a significant difference is seen, then we have labeled this rehabilitation approach "Effective." If only one or two of the several evaluation metrics are not affected by game-based rehabilitation, then we label them "Partly effective." Finally, if there is no significant difference in all evaluation measures before and after the intervention, we label them "No effective." In the following, the distribution of the reviewed studies based on effectiveness is shown in Figure 7

Discussion
is survey's main objective was to review the studies in which games were applied for improving the physical functions and rehabilitation of poststroke patients.  Journal of Healthcare Engineering 5    Journal of Healthcare Engineering 9    Journal of Healthcare Engineering 13 14 Journal of Healthcare Engineering   16 Journal of Healthcare Engineering   According to results, emerging games possess the capacity and potential to rehabilitate physical aspects in poststroke patients; furthermore, these games can help patients improve their independence. According to surveys, virtual reality-based approaches and "the Nintendo Wii Fit" games were used more than other games. e most common use of games in poststroke survivors' rehabilitation was related to limb movement and balance training. Due to the included studies' results, different indicators and scales have been calculated and statistically analyzed to evaluate and test game-based physical rehabilitation therapies for poststroke patients. ese statistical analyses demonstrated the positive effect of innovative rehabilitation is provided in the form of games for these patients. Even in many studies, applied games in different environments (virtual reality, and video-based games) have led to a great improvement in patients' physical problems such as balance disorder, upper extremity spasticity, and limbs' immobility and muscular weakness [3,5,11,[74][75][76][77]. Researchers in these studies have concluded that they can incorporate these games into the treatment plan and physiotherapy of poststroke patients and use them as alternative therapies to traditional methods because, in these experimental studies, significant improvements in all outcome measures were found after the intervention [76,78]. However, in infrequent articles, no significant differences can be observed in all assessment scales (baseline and post-intervention assessments in the experimental and control groups) to evaluate game-oriented physiotherapies' effectiveness. For this reason, in these studies, the researcher has concluded that the  [38,76], the high mean age of patients in both intervention and control groups (underlying disability of people due to their age), and excessive movement limitations of the patients recruited in the study [79,80].
According to this study's results, the most popular type of game for physical rehabilitation of poststroke patients was virtual reality games. Virtual reality-based games allow patients to interact with a virtual environment while performing rehabilitation exercises and simulating real       ese games increase patients' motivation to perform rehabilitation exercises and provide a pleasant environment for patients, which can lead to more repetition of rehabilitation exercises in these patients [77]. People get feedback while playing virtual reality games, and this factor encourages patients with disabilities to attend therapy sessions and use their remaining functional capacity to succeed in the game [81].
Results have shown that "the Nintendo Wii Fit" games are used more than other games to rehabilitate poststroke patients. Several factors can lead to the most use of this game. Among these factors, we can mention the price of these games, which are relatively inexpensive. ese games are widely available to people, and studies have shown that providing an attractive environment increases patients' enjoyment and more repetition of rehabilitation exercises [82][83][84]. Features of the Wii Fit game system lead to the stimulation of people's interest in continuing to play and can be useful for improving motor function and balance control [61].
Studies showed that the most common use of games in the rehabilitation of stroke survivors was related to limb movement and balance training. In other words, the results of studies that were run to examine the effect of games on people after a stroke had shown these games were effective in improving the balance of people and strengthening the muscles of the limbs [85]. In a systematic review conducted by Corbetta, the effectiveness of virtual reality games has   been investigated and concluded that managed games have the most significant impact on patient mobility [75]. According to the results of this survey and other studies that show the effect of the game on maintaining balance and movement, it is recommended to use these games in poststroke survivors.
is systematic review had several strengths and limitations. One of the strengths was the use of broad keywords to search in 4 crucial databases. Another strength of this survey was the inclusion of studies presented at conferences. e limitations were the exclusion of articles in non-English language and the time limit imposed on searching databases (from 2014 onwards). Another limitation of this review was the different scales used to measure people's performance, and this factor made it difficult to compare the results of different surveys.

Conclusion
Game-based approaches lead to patients being able to smoothly perform their rehabilitation movement techniques without going to the treatment centers. ese games can immerse the person in the environment by providing virtual or augmented reality capabilities and multiplying the effectiveness of the treatment. erefore, the use of appropriate technology-based gaming solutions can improve patients' treatment and minimize the waste of time and cost of providing traditional motor rehabilitation. Consequently, these game-based treatments are considered complementary to traditional ones and can reduce the workload of therapists and accelerate the rehabilitation process. Future research should focus on how task-specific game-oriented systems can improve function after stroke, and statistical studies can show this effect more.

Data Availability
All data generated or analyzed during this study are included within this article.

Conflicts of Interest
e authors declare that there are no conflicts of interest.