ExerG: adapting an exergame training solution to the needs of older adults using focus group and expert interviews

Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 https://doi.org/10.1186/s12984-022-01063-x RESEARCH ExerG: adapting anexergame training solution totheneeds ofolder adults using focus group andexpert interviews Nathalie Ringgenberg1*†, Sarah Mildner2†, Marcia Hapig3, Sarah Hermann4, Katharina Kruszewski3, Anna Lisa Martin‑Niedecken5,6, Katja Rogers7, Alexandra Schättin6, Frank Behrendt4, Sonja Böckler5, Stefan Schmidlin5, Roman Jurt5, Stephan Niedecken6, Christian Brenneis8,9, Leo H. Bonati4,10,11, Corina Schuster‑Amft1,4,12† and Barbara Seebacher9,13,14† Abstract Background: Exergames are playful technology‑based exercise programs. They train physical and cognitive functions to preserve independence in older adults (OAs) with disabilities in daily activities and may reduce their risk of falling. This study gathered in‑depth knowledge and understanding of three different user groups’ experiences in and relevant needs, worries, preferences, and expectations of technology‑based training, to develop an exergame training device for OAs. Methods: We conducted a qualitative study using semi‑structured focus group interviews of primary (OAs in geriatric or neurological rehabilitation) and secondary (health professionals) end users, as well as expert interviews of tertiary end users (health insurance experts or similar), exploring user perspectives on adjusting an existing exergame to OAs’ needs. Voice‑recorded interviews were transcribed by researchers and analyzed using thematic analysis (TA) following an inductive, data‑driven, iterative approach. Results: We interviewed 24 primary, 18 secondary, and 9 tertiary end users at two rehabilitation centers in Austria and Switzerland. Our TA approach identified five to six themes per user group. Themes in the primary end user group reflected aspects of safety, training goals, individuality, game environment, social interactions, and physical and technical overload. Themes in the secondary end user group comprised facets of meaningfulness, distraction through the game environment, safety, gamification elements, the availability and accessibility of the exergame. Tertiary end users’ themes addressed aspects of financial reimbursement, suitable target populations, professional training for the handling of exergame devices, training goals, and concerns about the use of exergames in geriatric rehabilitation. Conclusions: In conclusion, an exergame for OAs must be safe, motivating and fully adaptable to the target group while promoting the return to or preservation of autonomy and independence in daily life. Our findings contribute © The Author(s) 2022. 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The Creative Commons Public Domain Dedication waiver (http:// creat iveco mmons. org/ publi cdoma in/ zero/1. 0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. Open Access †Nathalie Ringgenberg and Sarah Mildner shared first‑authorship †Corina Schuster‑Amft and Barbara Seebacher shared last‑authorship *Correspondence: [email protected] 1 Department of Sport, Exercise and Health, University of Basel, Basel, Switze rland Full list of author information is available at the end of the article Page 2 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 Background Approximately one third of older adults (OAs) aged 65 and over fall at least once a year. The fall incidence increases with age and frailty, which stresses the need for targeted interventions [1]. Fall-related costs are increasing annually worldwide, placing a burden on affected individuals, families, and the health care systems [2]. Several factors underlie an increased risk of falls in OAs, with the most significant being functional limitations, balance and gait impairments [3]. These frequently result from an age-related loss of muscle mass, bone density, and muscle strength [4]. Aside from physical limitations, cognitive impairment increases the fall risk [5, 6] and represents a major cause of fall-related fractures, particularly in combination with osteoporosis [3]. Injuries or hospitalizations may increase the fear of another fall in individuals, followed by avoidance behavior and progressive immobility, which in turn accelerates the loss of muscle mass and promotes further falls [4]. Physiotherapy interventions are recommended to reduce the risk of falls and should include strength and walking training, as well as function-based exercises [7]. In addition, the results of a recent meta-analysis support the implementation of cognitive exercises in physical activity programs [8]. Playful technology-based exercise programs, known as exergames, can boost performance motivation and adherence [9]. The word exergame is a combination of the terms “exercise” or “exertion” and “video game” and refers to a training approach with which video games are played through body movements [10]. Furthermore, exergames may create an ecologically valid training environment as they resemble activities of daily living such as walking, climbing stairs, shopping, and preparing meals [11]. Other authors have suggested that older individuals’ fall risk decreases following training using innovative technologies [12]. Through gaming environments, older individuals are distracted from their actual exercise performance and effort, which is associated with higher levels of motivation [12]. Generally, OAs prefer exercises relevant to their everyday lives, supporting the use of training activities of daily living within an exergame program [13]. The rapid advancement of digital technologies and limited experience in the digital domain can lead to a barrier to utilizing innovative technologies in older individuals [14]. To enable OAs to safely use exergames, and avoid overwhelming them which might cause rejection of the experience, games must be adapted in an age-appropriate manner [15]. So far, there are few providers who specialize in exergames for OAs and even fewer who provide specific exergame solutions for geriatric rehabilitation, among them being Dividat Senso (Dividat AG, CH) and Silverfit Virtual Cycling (Silverfit B.V., NL). In this study, we aimed to gain in-depth knowledge and understanding of primary (older adults, PEU), secondary (health professionals, SEU), and tertiary end users’ (health insurance experts or similar, TEU) previous experiences in technology-based training, as well as their needs, worries, preferences, and expectations, to develop an exergame training solution for OAs. A deeper understanding of end users’ experiences, needs, worries, preferences, and expectations gained in this study will help to develop the concept for hardand software modification of an exergame training solution (ExerG). The future ExerG is expected to provide diverse training opportunities in the physical and cognitive domains. These training opportunities could help reducing the risk of falls. The research question guiding this study was: what are the end users’ experiences, needs, worries, preferences, and expectations towards an exergame training solution for OAs? Methods Study design This study used a qualitative approach consisting of semistructured interviews to gain in-depth knowledge and understanding of PEUs’, SEUs’, and TEUs’ experiences, needs, worries, preferences, and expectations regarding technology-based exercise training, specifically exergaming. Findings will be used to extend the ExerCube fitness exergame [16, 17] to the ExerG to target the needs of OAs. Figure1 shows the initial exergame (ExerCube), first illustrations (ExerG mock-up) and the first prototype of the target exergame device (ExerG). Information reported in this study follows the qualitative research review guidelines (RATS, see Additional file1) and Standards for Reporting Qualitative Research (SRQR, see Additional file2) [18, 19]. Figure2 presents the study procedures. to developing hard‑ and software extensions for the ExerG training device. Further research is needed to expand the validity of our findings to larger populations. Keywords: Focus groups, Exergaming, Virtual reality, Older adults, Geriatrics, Rehabilitation, User‑centered design, Exercise rehabilitation Page 3 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 The focus of this study was the subjective experience of the target groups. Therefore, an inductive qualitative approach was chosen, to holistically capture participants’ thoughts [20]. Thus, OAs with all their complexities were at the center of the investigation. To capture this complexity, an analytic interpretive orientation was chosen that attempts to stay close to the participants’ voices in the collected data, specifically the “hermeneutics of empathy” according to Braun and Clarke [20]. The aim of this approach is to understand the participants’ reality or views on topics and make sense of it [20]. In the PEU and SEU groups, the interviews were conducted as a focus group to encourage discussion among the participants. The group setting was intended to encourage participants to add to each other’s thought processes in order to elicit as much as possible about the topic [21]. The group size (aiming for 20 PEUs, 16 SEUs, 4 TEUs) was set to be small enough to allow each participant to have their say and large enough to achieve a diversity of opinion [22]. Participants were allocated to focus groups on a pragmatic approach based on the time of their consent for participation. TEUs were specifically selected and interviewed individually using expert interviews [23]. Sampling Using convenience sampling, the rehabilitation centers (Reha Rheinfelden, RHF, Switzerland; Clinic for Rehabilitation Münster, RZM, Austria) recruited PEUs, SEUs, and TEUs. The PEUs were recruited from the pool of in-patients with neurological, neuro-orthopedic and geriatric diseases of the respective rehabilitation centers who are prone to falls. Eligibility criteria for study participation in the PEU group were being ≥ 65years old (a), cognitive status allowing them to understand the study procedure/ content and informed consent (b), able to walk with or without a supportive device for 10m, or if wheelchairdependent, being able to sit in a wheelchair without arm and back rests (c). PEUs were excluded if they presented with a joint contracture (shoulder, knee, hip) Fig. 1 Adaptation process of an exergame training device (ExerCube) for older adults (ExerG) ©Sphery, CH Fig. 2 Overview of study procedures Page 4 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 (d), psychiatric disease (e), terminal illness with a life expectancy of less than 12months (f) or intense pain during movement (> 5/10 points on the Visual Analogue Scale [24]) (g). The SEUs consisted of physiotherapists, occupational therapists, sports scientists, and psychologists working at the rehabilitation centers. The TEUs were health insurance executive experts working for national (AUT, CH) or international governmental or non-governmental health associations. Recruitment The PEUs and SEUs were recruited at the rehabilitation centers RZM and RHF. Daily patient entry lists were screened for potential candidates, who were approached by a project member to inform them about the study in oral and written form and the voluntary participation opportunity. Upon providing initial consent, interviewees were screened based on the eligibility criteria. If all criteria were met, an appointment for a focus group interview was scheduled. Participants did not miss therapy sessions from participating in the focus groups. For the recruitment of SEUs, emails were sent to all therapists of the respective rehabilitation centers asking if they were interested in participating. After initial agreement, tentative dates were offered to agree on a group interview date. TEUs were informed about the project by email. Contact details were selected from personal contacts or previous collaborations. After agreement to participate, a date for an individual online interview was scheduled. All participants provided their written informed consent. Focus group / interview setting andguide Three to six PEUs / SEUs participated in each focus group on location, while TEUs were interviewed individually online. Focus group interviews were conducted in a quiet conference room with all interviewees sitting around a table. A visual interview presentation was given to support the discussion. Short breaks were included when necessary. One researcher acted as a moderator and led through the interview and discussion, while another researcher was responsible for technical support and taking field notes. A semi-structured interview guide using open-ended questions was prepared for each end user group and applied identically in both rehabilitation facilities [25, 26]. The dimensions and questions of the guideline were developed based on different models and existing questionnaires mainly coming from the field of Human– Computer-Interaction, such as the Game Flow Model [27] the Dual Flow Model [28] and the Physical Activity Enjoyment Scale [29].The guideline went through several iterations and was used in other previous exergame projects [17, 30] before it was adapted for purpose of the focus groups and expert interviews presented in this paper. Questions were designed to stimulate focus group discussion in the focus group, allowing the moderator the flexibility to explore certain topics with open and follow-up questions (see Additional file3). The openness of the questions was necessary to allow for diverse perspectives in the field of inquiry whilst still providing the necessary interview structure [23]. To ensure a basic level of mutual understanding, the topic and some technical terms were defined at the beginning. All SEUs already had experience with the use of exergames. The TEUs reported to have utilized exergames themselves, observed patients training with exergames or to be at least familiar with the goals and types of exergames. Introductory questions about individual experiences with games, movement, and technology were asked, followed by questions about technology and usability of exergames, data protection, exercise training, and social aspects. The ExerG training device concept was presented to all user groups using a prototype video and illustrations to gain a broad understanding of exergames. The presentation was adjusted to potential auditory and visual impairments of OAs and therefore pre-tested with six PEUs and four SEUs to refine the wording of the questions and better comply with the proposed duration of 90 min. For the TEUs, a specific semi-structured interview guide was used. Data collection andmanagement Demographic and professional data such as age, profession, work experience, previous knowledge of or experience with technology-assisted training were collected by screening medical records of the PEUs, direct questioning, or an on-site (RZM) or online (RHF) questionnaire. The Mini Mental State Examination (MMSE) [31] was used for assessing cognitive function, with a cut-score of < 24 indicating cognitive impairment [32], and the Barthel Index (BI) [33] and Extended Barthel Index (EBI) [34] were employed for evaluating daily functioning. With participants’ consent, all interviews were digitally recorded on two redundant digital voice recording devices to avoid loss of data. Recorded interview data were transcribed verbatim and anonymized according to the extended transcription rules of Dresing and Pehl [35] by a researcher of the respective rehabilitation centers or a professional transcription service (Transkripto, Rotterdam, Netherlands), depending on the time resources of the study teams. For transferring the recorded interview files to Transkripto, the company signed a non-disclosure agreement, and the data were Page 5 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 transferred through a Secure Sockets Layer computer network to guarantee secure communication. To verify the appropriateness of the transcripts, a researcher from the respective rehabilitation centers conducted a peercheck of several randomly selected transcript passages. Qualitative data analysis: coding andtheme development After confirmation of the transcripts’ accuracy by a peer, qualitative data were analyzed inductively using Thematic Analysis (TA). This approach was chosen because it provides a great deal of flexibility in analysis and can be applied to different ontological and epistemological positions. TA provides a set of basic core techniques and skills that are also used in other types of qualitative analysis [36]. TA identifies and organizes themes that appear important to the analyst for answering a research question [37]. MAXQDA (VERBI GmbH, GER) and f4 (dr. dresing & pehl GmbH, GER) software were used for thematic coding. We chose an inductive, data-driven coding approach for our TA. After familiarization with the data sets, codes were derived a posteriori through examination of the generated data [38]. By coding bottom-up from data, a realist ontology and constructivist epistemology were used to generate an understanding of interviewees’ subjective experiences and motivations [20]. Ontological realism claims that there is a reality independent from human minds whereas constructivism maintains that people create new knowledge through interaction and sharing of their ideas and experiences [39]. Using an iterative process, two independent coders analyzed the transcripts separately per center for PEUs, SEUs, and TEUs. Separately developed codebooks were then discussed among researchers from both centers to establish similar standards for theme development (see Fig. 3). Subsequently, themes were developed together using various rounds of discussions among coders. Themes were revised and refined several times by two junior researchers who were supported by five experienced researchers. All themes should be understood interpretively because the statements are speculative and not definitive. This process was repeated for SEUs and TEUs. Statistical analysis Statistical analyses were performed using IBM SPSS software, version 27.0. (Armonk, NY). Descriptive statistics were used for the demographic, professional, and disease-specific variables. Due to the small sample size, no inferential statistics were performed. Continuous data were checked for a normal distribution using the Shapiro Wilk Test, Q-Q plots, and histograms. Raw count (absolute and relative frequencies, N (%) was presented for count (walking aids) and nominal data (gender, profession, education level). Medians (minimum– maximum; 25th and 75th percentiles) were reported for ordinal data (MMSE, BI and EBI) and mean (standard deviation, i.e., SD) for continuous data (age, years of education and professional experience, and number of falls). Fig. 3 Thematic analysis process in this study Page 6 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 Results Participants’ characteristics The study was conducted from August to December 2021. In total, 24 PEUs, 18 SEUs, and nine TEUs were included. Figure 4 shows the flow chart for the PEU group. Focus groups with PEUs each included six patients at RZM and three patients at RHF, respectively. Mean age of PEUs was 75.7 (65–82) years. Focus groups in SEUs each included five therapists or psychologists at RZM and four therapists at RHF, respectively. SEUs’ mean age was 35.3(25-52) years. Participant characteristics of PEUs, SEUs, and TEUs are presented in Table2. Primary end users’ perspectives onexergames We identified six themes through TA in our PEU focus group data (Table3). These themes highlight the complexity of PEUs’ experiences, needs, worries, preferences, and expectations for an exergame training solution for OAs. In the following, we present the themes with key example quotes. For all themes identified, more quotes from the interviews can be retrieved from the appendix (Additional file4). 1. The game environment distracts OAs from the physical and mental effort during training. PEUs expressed that the game environment could reduce boredom and monotony during training. This distraction would allow OAs to exercise in a more relaxed manner. A bicycle path or forest trail as a digital environment could motivate them to exercise: P08: “Yes, I could imagine that you take a bit of the boredom out of the training program at home, when you work out on the home trainer using training equipment. And at the same time, you see a route that you like and that interests you: a bike path or a forest trail where you can do biking as well. Of course, that would be much more motivating. I could continue the path next time and drive across Austria, for example.” (RZM_ PEU2, paragraph 82) 2. Social relationships are of great importance and should be included in an exergame either through physical presence of therapists or direct interaction with therapists or co-players. It became clear that PEUs very much appreciate social interaction during their training. Personal care was considered important by OAs and must not be replaced by devices: P05: “Of course it is interesting, all these devices and suggestions. What I would miss is the human being in it, the personal attention. Or being cared for, or whatever.” (RZM_PEU1, paragraph 493) Social interaction can occur with co-players, as well as with therapists. Interviewees described that training with co-players could create cohesion and ambition. Therapists’ influence during training also seemed to matter to participants. A strong and trusting relationship with the therapist was considered essential. In their opinion, the therapist is responsible for guiding exercise performance and interpersonal aspects (e.g., motivating or showing empathy). P17: “[I need someone] who knows me inside out and instructs: ‘You have to speed up’/ (.) well, I cannot hang out there in a cool way/ (.) no, you have got a tough guy at the back there who can give you a little push! Right? And/ (.) but the praise comes at exactly the same time: ‘Hey, great, you showed a good commitment!’ And the therapist knows you.” (RHF_ PEU4, paragraph 698) 3. Due to the ageor illness-related limitation of their personal agency, OAs desire safety during the training. This theme reflects patients’ physical limitations due to their age or illness. To avoid injury, PEUs desired to be Fig. 4 Flow chart of primary end user study participants recruited in Reha Rheinfelden (RHF) and Clinic for Rehabilitation Münster (RZM) Page 7 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 safe during training. With optimum safety precautions, such as the presence of a therapist or using handrails, they expect they can actively participate in the game. P01: “Yes, it [safety] is very important, because I am not allowed to fall anymore.” (RZM_PEU1, paragraph 316) The ExerG training device will be equipped with a safety harness to prevent falling. According to one participant, surfaces that are touched as part of the game tasks should be soft to minimize the risk of injury. This would allow participants to feel safe enough to independently perform the exergame tasks: P06: “Yes, to put on the harness, this safety thing first, and maybe give instructions: ‘Nothing will happen to you and now it will take a quarter of an Table 1 Participant characteristics of primary, secondary, and tertiary end users * Use of a wheelchair or walking aid such as rollator or walking stick Primary end users (n = 24) Age in years (Mean (standard deviation; minimum–maximum)) 75.7 (5.8; 65–82) Gender: males / females (Frequency (percentage)) 15 (62.5) / 9 (37.5) Walking aid* (Frequency (percentage)) 11 (45.8) Mini Mental State Examination (Median (25th, 75th percentiles; minimum–maximum)) 29 (27, 30; 24–30) Barthel Index (Clinic for Rehabilitation Münster) (Median (25th, 75th percentiles; minimum–maximum)) 100 (83, 100; 70–100) Extended Barthel Index (Reha Rheinfelden) (Median (25th, 75th percentiles; minimum–maximum)) 59 (56, 62; 45–63) Fall prevalence over the last six months (Frequency (percentage)) No fall 9 (37.5) Up to five times 5 (20.8) More than five times 1 (4.2) Diagnoses (Frequency (percentage)) Ischemic or hemorrhagic cerebrovascular insult 8 (33.3) Parkinson’s disease 6 (25) Multiple sclerosis 2 (8.3) Tick‑borne encephalitis 1 (4.2) Lumbar spinal stenosis with hip flexor paresis 1 (4.2) Structural epilepsy 1 (4.2) Polytrauma 1 (4.2) Spinal disc herniation 1 (4.2) Polyarthrosis, osteochondrosis with vertigo 2 (8.3) Multimorbidity 1 (4.2) Secondary end users (n = 18) Age in years (Mean (standard deviation; minimum–maximum)) 35.3 (7.5; 25–52) Gender: males / females (Frequency (percentage)) 8 (44.4) / 10 (55.6) Profession (Frequency (percentage)) Physiotherapist 10 (55.6) Occupational therapist 2 (11.1) Sports scientist 4 (22.2) Psychologist 2 (11.1) Work experience in years (Mean (standard deviation; minimum–maximum)) 9.0 (6.2; 0.5–20) Education level (Frequency (percentage)) Bachelor´s degree 4 (22.2) Master´s degree or equivalent 9 (50.0) Doctoral degree 3 (16.7) Others 2 (11.1) Tertiary end users (n = 9) Age in years (Mean (standard deviation; minimum–maximum)) 49.7 (9.4; 31–59) Gender: males / females (Frequency (percentage)) 6 (66.7) / 3 (33.3) Work experience in years (Mean (standard deviation; minimum–maximum)) 26.7 (10.7; 4–38) Education level (Frequency (percentage)) Bachelor´s degree 1 (11.1%) Master´s degree or equivalent 3 (33.3) Doctoral degree 4 (44.4) Others 1 (11.1) Page 8 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 hour’. And when you touch something, it has foam rubber or something like that (.). Then no one would have to stand by me (.) during the [game].” (RHF_ PEU1, paragraph 465). According to some participants, the feeling of being secured would increase one’s self-confidence to move outside the usual comfort zone. 4. OAs worry about feeling physically as well as technically overwhelmed. A lack of experience and concerns regarding the exposure to computer game addiction additionally leads to hesitancy regarding technology use. PEUs do not consider themselves digital natives. They have little to no experience with technology-assisted therapy and often think critically about it. Participants were afraid of being overwhelmed, suggesting that a userfriendly interface adapted to them is of key importance. Despite the user-friendly interface, training with the ExerG should only occur after professional training of the OA by SEUs, illustrated by the following example: P05: “I think that is good, but it does not seem so easy and for me it would be very difficult to take part in it. I am interested, but I find it very demanding. At least considering my present condition. Very difficult. I would almost be a little overwhelmed with certain things.” (RHF_PEU1, paragraph 375) Factors for OAs’ disinterest in exergames ranged from general disinterest to insufficient knowledge about the use of digital devices. Another factor contributing to the distrust of computers or exergames was the fear of game addiction, which was mentioned only by a few participants: P10: “An online card game, I cannot think of the name now (...). I played that passionately, almost addictively, and with a lot of effort I got out of the habit, because I realized how long I spend playing [online] and that is not good for me. I do not play other games at all/. I am not interested in that.” (RZM_PEU2, paragraph 37) 5. Narratively realistic training that focuses on activities of daily living (ADL) is desired to manage daily living as independently as possible. Independent coping with everyday life is a high priority for PEUs. The data showed that training tasks which are closely related to everyday life activities within an exergame intervention would present a way to increase motivation. A mock-up video of an exergame that can be used to simulate shopping at the supermarket was shown to the focus group participants as an instrumental activity of daily living. Patients’ responses demonstrated an increased interest in using an exergame if situations close to everyday life can be trained: P10: “It was very close to reality, so it was easy to empathize. [...] My first thought was that I could relate to it.” (RZM_PEU2, paragraph 238) Self-stated goals of the PEUs reflected the importance of ADL. Above all, the independent ability to walk was in the focus. Patients stated that an improvement visible in their ADL would motivate them to continue exercising. The following excerpt shows that the PEUs were aware of their ability to achieve their goals through regular training in therapy: P05: “There must be more stability (..) I am an insecure walker or (.) sometimes a little dizzy and so on and I am here to improve that with a therapist. Learning to walk properly again or and that is the main goal, that I walk again, independently (.) like before.” (RHF_PEU1, paragraph 220) Table 2 Themes resulting from the thematic analysis of primary end users’ data PEU primary end user, OAs older adults, ADL activities of daily living Primary end users 1 The game environment distracts OAs from the physical and mental effort during training 2 Social relationships are of great importance and should be included in an exergame either through physical presence of therapists or direct interaction with therapists or co‑players 3 Due to the age‑ or illness‑related limitation of their personal agency, OAs desire safety during the training 4 OAs worry about feeling physically as well as technically overwhelmed. A lack of experience and concerns regarding the exposure to computer game addiction additionally leads to hesitancy regarding technology use 5 Narratively realistic training that focuses on ADL is desired to manage daily living as independently as possible 6 A wide variety of individual customization options are desired to increase motivation through successful exergame experiences Page 9 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 In addition to the ability to walk, hobbies were also regarded as important. These are often no longer possible, due to physical limitations or the risk of falling. 6. A wide variety of individual customization options are desired to increase motivation through successful exergame experiences. This theme reflects various customization ideas for the exergame suggested by the PEUs. The type of activity, but also the difficulty level should be adjustable according to the interviewees: P08: “But I still see a big advantage with computer assisted video games, you can introduce practically any level or any performance standard. I can do penalty shootouts today against Christiano Ronaldo and this is facilitative, to make the game more exciting or increasingly more exciting. Or I can play tennis against Dominic Thiem. It is all conceivable.” (RZM_PEU2, paragraph 164). With adaptive levels of difficulty, the interviewees expect they would be able to perceive improvements that they make themselves. Several participants mentioned this as a way to promote motivation and stimulate performance. Exergames should therefore enable the visualization of small improvements: P15: “Then it becomes difficult to maintain one’s motivation. […] Yeah, if you do not see the progress.” (RHF_PEU4, paragraphs 561–563) Secondary end users’ perspectives onexergames We identified six main themes through TA in our SEU focus group data (Table4). 1. From the SEUs’ perspectives, a functional and individualized meaningful game design is of great importance to OAs for increasing training motivation. SEUs expressed that training goals must be individually selected and specified very precisely, allowing OAs to find them meaningful to themselves and motivating them to exercise in rehabilitation: S02: “I also have the impression, [… that] if they simply train their balance specifically for THAT [ADL or sports activities], where they need it, they are also more motivated and simply (...) more involved in the therapy than just doing some exercises, where they do not know whether they need them in everyday life.” (RZM_SEU1, paragraph 21) Regarding the exergame, SEUs desired high quality and realistic graphics, sound, and story. They imagined natural game environments (e.g., a forest or city walk) being more attractive to OAs than a virtual fantasy environment. They suggested ‘useful’ and functional activities like picking mushrooms in the forest instead of touching points of light to achieve a high score in a racing game. In their opinion, training should be adapted to individual functional goals. Functional exercises which are meaningful and relevant for their everyday lives, should be provided for various sports activities or ADLs in the exergame. A supermarket visualization where OAs perform everyday movements (e.g., a type of squats) as training was particularly well received: S08: “Somehow transfer that [personal interests] into the game. Or then you picked things up, did squats or something like that/. […] And then you walk through the store because you want to take something out of the bottom shelf. Well, I think that calls for such a system.” (RHF_SEU2, paragraphs 1082-1084) Table 3 Themes resulting from the thematic analysis of secondary end users’ data SEUs secondary end users, OAs older adults Secondary end users 1 From the SEUs’ perspectives, a functional and individualized meaningful game design is of great importance to OAs for increasing training motivation 2 The fall protection device in the ExerCube is expected to provide OAs with a feeling of safety that will allow them to train at their individual performance limits 3 Based on the therapists’ experience, digital gamification in therapy leads to an increased motivation in OAs 4 The game environment provides an opportunity to distract OAs from their functional limitations and allows them to unconsciously move more freely 5 The availability and perceived time demands of an exergame may limit its usability 6 A lack of local accessibility to and availability of the exergame after discharge from a rehabilitation center and an unawareness of alternative, non‑ computerized training strategies may influence adherence negatively Page 16 of 17 Ringgenbergetal. Journal of NeuroEngineering and Rehabilitation (2022) 19:89 Additional file2. Standards for reporting qualitative research (SRQR) checklist, Completed SRQR checklist with page number information of the main manuscript text. Additional file3. ExerG—Semi‑structured interview guide, Interview guide with procedures and prepared questions for the semi‑structured interviews with primary, secondary, and tertiary end users. Additional file4. Detailed list of end users’ verbatim quotations, Verbatim quotations, and supplementary quotes from the interviews for primary, secondary, and tertiary end users. Acknowledgements We would like to express our very great appreciation to every end user who participated in our study. Their valuable and constructive opinions, experiences and stories during the interviews contributed massively to this research work. Author contributions The authors AM‑N, AS, BS, CB, CS‑A, FB, KK, KR, LB, MH, NR, RJ, SB, SH, SM, SN and SS were involved in the study conception and design. BS, CB, CS‑A, KK, MH, NR, SH and SM screened and recruited the participants for this study, while BS, CS‑A, FB, NR, SH and SM collected the data (conduct of interviews, case report forms). Data analysis and interpretation of results (transcription, thematic analysis) was performed by AM‑N, BS, CS‑A, KK, KR, MH, NR, SH and SM. The authors BS, CS‑A, MH, NR and SM were responsible for the manuscript draft preparation (writing process). All authors reviewed, read and approved the final version of the manuscript. Funding The ExerGetic project is co‑funded by the AAL Programme and the national authorities in Austria (Austrian Research Promotion Agency, FFG), Canada (Canadian Institutes of Health Research, CIHR) and Switzerland (Innosuisse) (project number AAL‑2020‑7‑48‑CP). The funding agency was not involved in designing the study, sampling and recruitment, data collection, data evaluation, or writing the manuscript. Availability of data and materials The datasets generated (transcripts, case report forms) and/or analyzed during the current study are not publicly available due to privacy reasons of participants but are available in an anonymized form from the corresponding author on reasonable request. Declarations Ethics approval and consent to participate This study was prospectively registered on 13.07.2021 with the German Clinical Trials Register (DRKS00025838). An ethics request (Req‑2021‑00621) was submitted to the ethics committee of Northwest‑ and Central Switzerland (EKNZ) by the research Department of the Reha Rheinfelden. According to the EKNZ, the project does not fall under the scope of the Human Research Act (HFG Art. 2 Abs. 1) and therefore an ethical approval was not necessary. In Austria, ethics approval was obtained from the ethics committee of the Medical University of Innsbruck (reference 1153/2021) on 02.06.2021. All participants provided their written informed consent to participate. Consent for publication Not applicable. Competing interests Besides their academic career, AM‑N, AS and SN also work for Sphery Ltd. AM‑N and SN are co‑founders of the start‑up company Sphery Ltd, that developed the ExerCube based on the results of previous research projects. AS has worked as Senior Research and Development Manager at Sphery since November 2019. The remaining authors have no conflicts of interest to declare. No revenue was paid or promised to be paid directly to AM‑N, to AS, to SN, to Sphery Ltd or the research institutions. Author details 1 Department of Sport, Exercise and Health, University of Basel, Basel, Switzerland. 2 Department of Health Sciences, IMC University of Applied Sciences Krems, Krems, Austria. 3 Research Center on Vascular Aging and Stroke, VASCage GmbH, Innsbruck, Austria. 4 Research Department, Reha Rheinfelden, Rheinfelden, Switzerland. 5 Department of Design, Subject Area Game Design, Zurich University of the Arts, Zurich, Switzerland. 6 Sphery Ltd, Zurich, Switzerland. 7 Stratford School of Interaction Design and Business, University of Waterloo, Waterloo, ON, Canada. 8 Department of Neurology, Clinic for Rehabilitation Münster, Münster, Austria. 9 Karl Landsteiner Institute of Interdisciplinary Rehabilitation Research, Münster, Austria. 10 Depar tment of Neurology, University Hospital Basel, Basel, Switzerland. 11 Depar tment of Clinical Research, University of Basel, Basel, Switzerland. 12 Institute of Rehabilitation and Performance Technology, Bern University of Applied Sciences, Burgdorf, Switzerland. 13 Department of Rehabilitation Research, Clinic for Rehabilitation Münster, Münster, Austria. 14 Clinical Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria. 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