Keywords

1 Introduction

Serious games are now an established field of study, and are games used for purposes other than pure entertainment [1]. These types of games are designed to be used for education and/or training. A subgroup of serious games is the exergames, which combine conducting exercises with playing games [2]. Examples are games related to sport or health where the user conducts physical activities to accomplish different tasks in the game. The usage of serious games is rapidly increasing in the field of health [3]. These games have a two-fold goal, both to increase motivation and to support education. This makes them complicated to develop and it is not uncommon that exergames (for health) are developed and tested solely by engineers, healthcare professionals and researchers. Often the actual users, patients and physiotherapists, are not involved actively during the development [4, 5]. Although there are examples where older users have been participating in the development, participation in the design process could be a challenge if the person suffers from severe physical or cognitive limitations.

When designing rehabilitation games for older adults, individual needs are important [6]. The technology, hardware and software, must provide possibilities to design exercises that may be adjusted to different levels of physical ability. Exergames, are based on camera-based controls, and displays a real-time video of the player on the screen. The user interacts with gestures and sometimes even by voice.

With respect to platform, two main categories of technologies exist, console and PC-based platforms. The PC platforms are more widespread than the consoles. Examples of commercial exergames used by health researchers and clinicians are Nintendo Wii, Kinect, Eye and Move [7, 8].

Although there are commercial games that are entertaining, it is necessary that games and exercises for rehabilitation or treatment are developed adapted for their intended target groups. Wii games may not be suitable for older adults because the interaction requires controlled and directed movements, which can be difficult for some groups of older adults. Video-capture systems like PlayStation EyeToy (track movement by cameras) have been described as more user-friendly with respect to older adults since the interaction is easier and more natural [9].

Exergames may be stimulating for older adults to stay active and for conducting exercises as a part of a training program. Successful usage depends on usage over a longer period of time, which entails that motivation to use and feedback on progress are important features [10], and several studies have shown how motivational features in an exergame can increase physical activity among older adults [11]. It is of utmost importance that the exergames are designed based on knowledge about the target group’s abilities, especially when it comes to frail users. However, there is a lack of specific guidelines adapting these games to e.g. older adults [12].

The purpose of this work was to present a categorized overview of existing design guidelines with respect to exergames for older adults, also covering specific target groups such as users undergoing rehabilitation or people suffering from a chronic disease, where large parts of the user groups are older adults. A second aim with the work was to enrich current design guidelines with own insights based on several projects that have been conducted in the area of developing exergames for rehabilitation and treatment purposes.

2 Towards a Framework for Guidelines Within the Area

This work consists of three parts: an overview of the literature in the area, a description of own related projects, and an analysis of existing guidelines based on own insights.

The literature review, presented in Sect. 3, covers existing guidelines for development of exergames targeting older adults, users suffering from a chronic disease and patients undergoing stroke rehabilitation. For each specific target group, guidelines from different sources have been merged with the aim of creating an overview of the guidelines.

The example projects described in Sect. 4 are within the area of stroke rehabilitation and Chronic Obstructive Pulmonary Disease COPD. In the stroke rehabilitation project, a tool for conducting exercises and follow-up was developed together with clinicians and patients. The project consisted of several phases and two versions of the prototype. The COPD exergame is a part of an ongoing project with development of a tool that promotes physical activity at home with monitoring and remote communication services.

These two projects gave us a number of insights not yet covered by the literature, both with respect to designs of tools for exergames and regarding practical issues that have to be taken into consideration when implementing tools and devices in peoples’ homes.

With respect to the analysis, initially, main areas or categories of guidelines were identified based on the literature review. The guidelines were categorized based on the topic they addressed and target groups. In a second step, the guidelines in each category were analyzed based on the experiences from developing exergames for these target groups. Similarities with existing guidelines were identified as well as aspects that were not yet covered by previous work in the area.

3 Design Guidelines for Sensor Based Exergames

Areas covered in this literature review regarding guidelines for design of exergames are: designing exergames for older adults; designing exergames for users with chronic diseases such as COPD and Parkinson’s disease; and designing exergames for physical rehabilitation after stroke or injury.

There are also standards for how user interfaces should be designed, e.g. the Web Content Accessibility Guidelines (WCAG), which are guidelines for facilitating usage of the Internet for older adults and people with different disabilities [13]. This work addresses the functionality in exergames, however, it should not be ignored that design of the user interface also needs to comply with other guidelines or standards that exist for older adults and people with disabilities.

3.1 Designing Exergames for Older Adults

Older adults are a heterogeneous group ranging from living an independent life to frail elderly living in nursing homes. Regardless, when designing games for older adults it is needed to take into account the impact of age-related decline such as cognitive decline (problem solving, processing of information) and decline in motor functions (modification in balance and posture, deterioration in fine motor skills). Bronx et al. [12] highlight decline in motor function among older adults, e.g. knee conditions, hip prostheses and balance problems (which also causes pain). Chronic diseases such as diabetes, Parkinson’s disease or heart conditions might also affect older adults’ ability to use exergames [14]. Exergames should provide different ways of performing exercises and motor skills should not prevent users from performing the exercises. Gerling et al. [14] discuss, within the context of game design for older adults, an approach where age-related changes should be viewed from a perspective to which extent they affect different elements of the game such as players, resources, user interface and outcome (for more details about the guidelines described by Gerling et al., see Table 1).

Table 1. Criteria to take into consideration when designing exergames for older adults.
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Bronx et al. [12] present important lessons learnt from three years of working with exergames for older adults. They provide a protocol for User-centered design (UCD) for the development of exergames for older adults. In order to achieve success, the designer has to spend time with the older adults to be able to understand their needs and preferences. Bronx et al. suggest game elements that to some extent may seem obvious, however they are important features to take into consideration. Examples of game elements and functionalities they address are speed, movements, information, menu and sound, which all need to be taken in to account when developing exergames for older adults (for more details about guidelines by Bronx et al., see Table 1).

A factor important to highlight in use of exergames is the social aspect, which is not covered by all guidelines in the area. Still, this is an important feature that might be beneficial to include in exergames for older adults. For a successful and prosperous ageing, self-acceptance and active involvement are important, which among other things can be achieved through social relationships with friends and family, e.g. by playing games [7].

With respect to older adults, as with others, the games must be challenging and entertaining to keep the user’s interest and attention. It has also been suggested that older adults like simple games and enjoy the social aspects of games such as multi-player games [6]. Perry et al. [6] highlight criteria when designing exergames for older adults in a post-stroke phase; however they are applicable for older adults in general. Their criteria address areas such as cognitive challenge, simple objective, feedback, creation of new learning, and appropriateness of genre (for more details about the guidelines by Perry et al., see Table 1).

Table 1 summarizes important criteria when designing exergames for older adults. Each criterion is illustrated with examples referring to the previous studies.

One point to add is the importance to take into account personal limitations and requirements that are not covered by the guidelines. Hence, it is necessary to include end-users in the development of exergames so that personal requirements may be elicited, designed for and tested. These users may also represent other potential users with similar individual needs or demands, i.e. level of difficulty or ability to use different input devices etc.

3.2 Designing Exergames for Users with Chronic Diseases Such as COPD and PD

COPD (Chronic Obstructive Pulmonary Disease) is a chronic disease where physical activity can promote better health. Within the area of COPD several services and products have been developed aiming at supporting self-management of the disease. In mild to moderate COPD, studies have shown that physical activity has a positive effect [16, 17]. Patients with COPD themselves are also aware of that exercising is an important part of pulmonary rehabilitation [18]. By reducing the progression of the disease, quality of life for the patients could be increased and large costs for the society could be reduced. Technical solutions could support monitoring and self-management of the disease, provide coaching and support exercising [19].

Tabak et al. [19] conducted a study showing that the technology they suggested was not sufficiently motivating for performing exercises at home. Their explanation to this was that the patients already knew the exercises from previous health care and that it was not motivating enough for the patients to do the exercises through a web portal. Based on these insights from Tabak et al. [19] a number of functional criteria for exergames targeted towards COPD patients can be formulated (see Table 2).

Table 2. Criteria to consider when designing exergames for COPD and PD patients.
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The benefits of physical activity for COPD patients are well known. Exercises such as aerobics and strength training reduce breathlessness and fatigue [17]. In a study conducted by Tabak et al. [19] the use of Nintendo Wii was explored as a way of increasing physical activity among COPD patients. This study provided useful insights with respect to important aspects to take into consideration when designing exergames for patients with COPD (see Table 2). However, further studies need to be conducted to investigate whether this type of exergames can be used in the home environment, and to which extent they can encourage patients with severe COPD to be physically active.

Another studied group of chronic patients are the ones with Parkinson’s disease (PD), which suffer from motor symptoms such as balance and walking problems. This, in turn, reduces mobility and lead to an increased risk of falling. Physical activity has shown to reduce these problems [20]. Based on [20] design criteria can be derived regarding how exergames could be adapted to PD patients aiming at supporting motivation and increase efficiency of the training (see Table 2).

Patients with COPD are a frail group and it is not uncommon that they also struggle with deteriorated movement functions. Therefore, it is extremely important to motivate them to perform any kind of physical activities, to support them in actually conducting the exercises, rather than performing well. The element of competition is less meaningful to this group. Here it is more about encouraging each individual on a personal level.

3.3 Designing Exergames for Physical Rehabilitation After Stroke or Injury

Neurological diseases or conditions such as Stroke requires long rehabilitation and demands large amounts of training [22]. The likelihood of stroke increases exponentially with age and most stroke patients are over 65 years old. This user group is therefore to large extent older adults, and they may also due to the disease suffer from visual and cognitive deficiencies that can affect their ability to read and understand instructions.

Exergames can be a part of rehabilitation at home. However, it is important that rehabilitation is carried out in a safe manner and that the training is effective in terms of achieving rehabilitation goals. Since commercial exergames do not meet all the requirements related to physical rehabilitation, specific games are required to be developed on top of the technologies used for gaming [23]. When developing exergames, exercise definitions and the gamification parts need to be differentiated for meeting the requirements for rehabilitation to be safe and the training to be effective [23]. With safety as the foundation and the most important aspect, Pirovano et al. [23] suggests a number of criteria for design of exergames targeted towards physical rehabilitation (see Table 3).

Table 3. Criteria to take into consideration when designing exergames for physical rehabilitation.
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Skaeret et al. [24] addresses a number of recommendations to succeed in creating exergames as a rehabilitation tool (exercise tool) for older adults. To engage older adults, exergames need to be adapted to each players individual goals and their performance level. The game should also include different types of physical functions (exercises) adapted to different needs for rehabilitation in older adults [24].

Technology of today allows for storing information about the exergame session for users. Such information can be used to enable personal feedback (e.g. how to adjust motion adjustments and customize player exercises). The information may also provide new knowledge about training routines, etc. More studies are required to prove whether exergames give rise to greater compliance than traditional training [24].

One important part in neurorehabilitation is to achieve improvements in Activities in Daily Life (ADL) [6]. ADL is a measure of a person’s ability to cope with basic and daily activities (dressing, walking, eating, etc.) in life. Therefore, rehabilitation games should be based on tasks/exercises that are in line with the functional goals of ADL. To achieve functional improvement in rehabilitation games, Perry et al. [6] proposes key factors along with appropriate tasks and environmental factors (for more details about the criteria described by Perry et al., see Table 3).

As mentioned previously, a large part of patients that undergo stroke rehabilitation are 65 years of age or older. Therefore, it is also important to take into account age-related decline when implementing exergames targeted towards rehabilitation (see Sect. 3.1). Finally, the entertainment part in gaming should not be ignored when it comes to rehabilitation. Motivation to play and to do exercises can be raised thanks to the entertainment part.

4 Examples of Own Projects Within the Area

4.1 A Stroke Rehabilitation Tool

In previous projects we have developed an exergame tool that supports motor training of stroke patients in their homes [25]. The tool combined interactive communication technology with a gaming environment that provided different exercises. The system consisted of a technical installation in the patient’s home and an installation at the rehabilitation clinic. The equipment in the patient’s home was a Kinect sensor, a big screen and a computer connected to the Internet. At the clinic the equipment consisted of a screen, a web camera and a computer connected to the Internet. The system provided support for planning, follow-up, and social interaction in terms of video communication with the physiotherapist.

The exercises were based on existing evidence-based rehabilitation methods and the exercises consisted of different levels of difficulty, where the first level aimed at getting the patient to perform the exercises properly. In the first version of the prototype simple games were developed. For example, one game displayed the patient’s body posture on the screen like a stick figure and the game challenge was to move the upper-part of the body to a marked position at the screen (see Fig. 1). The patients received real-time feedback whether the exercises were performed in a correct manner. In the second version of the prototype, the gaming environment had been developed further and the interaction was more similar to commercial games (see Fig. 1).

Fig. 1.
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The stroke rehabilitation tool (First version of the prototype to the left, second version to the right)

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When choosing technology, one of the most important requirements was that it should be easy to install and easy to use in a home environment. Another requirement was a fun and easy-to-play game environment where patients would be motivated to exercise. The motivational aspect was important since a large amount of training is required to achieve the rehabilitation goals. The tool was developed in an iterative way together with physiotherapists and patients. The first version of the prototype has been tested in a feasibility study, where fifteen stroke patients used the tool in their homes for three weeks [26]. The second version will be tested in an ongoing project.

4.2 A Tool for Users with COPD

A tool for users with COPD is being developed in an ongoing project. The tool promotes physical activity at home with monitoring and communication services at a distance [29]. The system consists of three main parts: a game based rehabilitation station, an app for Android and iOS systems and a web interface for healthcare professionals. The games have been designed primarily for COPD patients, stroke patients and for fall prevention, but have a potential to be generalized to other situations as well.

The caregiver utilizes a web-based interface to plan activities, monitor physical activities and health states, and to follow up and communicate with the patients. This enables the creation of tailored treatment programs for individual patients based on their needs and conditions. An integrated audiovisual communication system enables the caregiver to interact with patients through live video and audio. A physiotherapist can thereby provide complementary feedback while the user performs exercises remotely. The involvement of healthcare professionals creates awareness amongst the patients that somebody is monitoring their progression. This has, alongside with the feeling of being seen, a positive effect on the physical activity.

The technology in the patient’s home consists of station with ordinary hardware products (a 27″ screen with a small computer on the back) and a Kinect motion sensor. The system identifies the user’s motion pattern and provides feedback when necessary to correct or improve the motion. Some of the games were designed based on common physical rehabilitation exercises and added into a suitable game environment. Other games were inspired by already existing popular games which where redesigned and analyzed to determine what benefits the motion pattern may offer. Different levels of difficulty have been created for each game in order to adjust for the user’s condition. Other than the game level, the load can also be adjusted by alternating the user’s performance position or by adding additional weights.

The app can be downloaded into a smart phone, or in case of lacking devices a tablet can be delivered together with the tool. In the app, the user can see planned activities, add comments to the activities, report on current health state, communicate with their care providers or other users of the system and follow up on results. The app is an important addition to the rehabilitation tool since it motivates and empowers the patients to participate in their own healthcare process. The social interaction is also an important feature aiming at supporting motivation.

A study has been conducted with respect to features and components to include in the system architecture [30]. Ongoing user testing is also performed with COPD patients and healthcare professionals from Angereds Närsjukhus (a Swedish hospital).

5 Categorization and Extension of Existing Guidelines

This section presents a categorized overview of existing design guidelines with respect to exergames for older adults, also covering specific target groups such as users undergoing physical rehabilitation after stroke or injury or people suffering from a chronic disease. Existing guidelines are also discussed and extended by own insights from developing exergames for these target groups.

5.1 Categorization of Existing Guidelines

Based on the literature described in Sect. 3, eight main categories were identified with respect to guidelines for exergames targeted towards older adults in general, for people suffering from a chronic disease such as COPD and PD and for physical rehabilitation purposes. The categories were: (1) Physical activity (design aspects addressing the exercises), (2) Cognitive decline (aspects to take into considerations if the user suffers from cognitive decline), (3) Devices and tools, (4) Tasks, goals and genre, (5) Environment, (6) Motivation and gaming mechanisms, (7) Social components and (8) Interaction and feedback (see Table 4).

Table 4. Eight categories of design guidelines
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5.2 Analysis of Existing Guidelines and Insights from Our Projects in the Area

Below, important guidelines or design guidelines are discussed and extended by own experience of working with exergames for older adults in general and for specific target groups such as users undergoing physical rehabilitation or people suffering from a chronic disease, i.e. COPD and PD.

Physical Activity and Exercises.

With respect to physical activity, one important design aspect for all described target groups was that the exercises have to be adapted towards the user and the specific context of usage [6]. However, with respect to older adults and users with chronic diseases the design recommendations had a stronger focus on maintaining abilities, while for patients undergoing rehabilitation the main focus was on achieving improvements. Based on own insights from developing tools for stroke rehabilitation [25] and for supporting physical activity among COPD patients [29] the distinction between maintaining abilities and achieving improvements has been evident. The games developed for the COPD patients supported physical activity in general and the main aim was to slow down the progress of the disease. The stroke rehabilitation games were based on specific exercises and well-established methods for evaluate ability to move. Regardless of target group or need for training, the exergames must be adjustable to a variety of needs and levels of difficulty. Our insights from developing exergames for COPD patients also placed an emphasis on the need to develop games for people that could be very frail. This user group needs exercises that are very easy and small amounts of exercise could have a large impact. For this user group it is also important that the system provides the possibility to conduct the exercises in the user’s own pace without stress or pressure. This might be the largest benefits from designing exergames specially targeted towards this user group [29].

Cognitive Aspects.

Games designed for older adults should take into consideration a decreased sensory acuity and longer response time [27]. With respect to cognitive aspects and design of exergames, the cognitive challenge needs to be on the right level, both in terms of content and instructions [13]. Even if guidelines targeting older adults suggest simple interaction and avoidance of distractions, our experiences reflect a more important aspect to consider cognitive limitations in terms of severe age-related decline or cognitive implications after neurological diseases such as stroke. To be able to provide meaningful training and a fun experience the games need to take different cognitive limitations into consideration, and be adjustable to a variety of limitations and also level of limitation. Simple interaction and avoidance of distraction is of course an important feature, however the challenge also has to be on a proper level and the game must not be perceived as childish.

Devices and Tools.

One of the guidelines suggested regarding devices and tools place a focus on the use of task-appropriate tools [6], which of course is an important aspect. This guideline consists of several subparts that to some extent varies based on the target group. When dealing with technology for home usage the devices must be possible to place in peoples’ homes. There must be enough space, both in terms of finding a place for the device and free space in front of the equipment. It must also be possible to conduct the exercises in a safe way without falling over furniture or other objects [26]. Our insights from testing an exergame with COPD patients were also in line with the above. The Kinect sensor and some of the games required quite a large amount of space. The exercises and the user’s body needed to be visualized on a screen and the user needed to be able to move around. This demand of space has resulted in difficulties with placement in patients’ homes, sometimes resulting in limited functionality of the exergame station.

Another important design feature is that the exergames should be able to gather relevant information and interact with the user in the intended way. Based on our experience from developing a stroke rehabilitation tool, this may be a problem when using camera based systems such as the Kinect sensor. That kind of technology cannot, for example, “see” when body parts that are crossing each other. As a conclusion from the work with COPD patients, we found that the Kinect sensor is a suitable solution for home based rehabilitation where the motion pattern consists of big movements that do not require precise tracking precision. The camera based systems also force the user to conduct the exercises at a designated spot. On the other hand, with camera based systems, the user does not have to put on wearable sensor equipment, which could be difficult when suffering from an injury or having affected body limbs after a stroke.

From a system and developmental perspective, it has to be decided if the game should be built on an existing game or if it should be a completely new product or service. With the latter one it will be possible to base the game design on movements that are desirable to include in the game, which is an advantage. Some types of exercise could be aimed at strengthening abilities that have been lost, and with designated design the games could support rebuilding these abilities in different ways. New evidence is continuously created and this knowledge can be used when developing exercises gaming tools. Therefore, the systems need to be adaptable to new knowledge and the need for new types of exercise. This flexibility must be built into the system [28].

Tasks, Goals and Genre.

As described in the guidelines clear and task oriented training goals should be defined [6]. These goals should also be based on individual abilities that may vary between different occasions. The goals should be able to use in follow-up of progress. This was also shown in the use of the stroke rehabilitation game that we developed [26], where the user found it important to be able to follow own progress and achievements. Both the individual and the care professional should be able to follow up reached results. This means that the tool should be able to store result for each exercise occasion. Results can be measured both related to how the types of exercises were performed, and also to intensity and regime definitions. Further, results can also be measured by performing specific assessment exercise types. Both the individual and the care professional should be able to follow up the results [29]. The exercise types need to be defined and placed in relationship to concrete goals. It is also important that the patient and the professional have the possibility to do follow up together in order to define new and/or modified goals that are relevant and reachable goals to keep the motivation and continuity. Intensity definitions and regimes should also be possible to define for the different exercise types. This is important since the exergame tools also need to be a part of a larger follow-up context around the patient. Activity types for the individual and a defined personal plan should be a part of the whole coherent plan for the individual [29].

Guidelines suggest the use of appropriate and adaptable challenges [6]. This is of course important since abilities can vary to a large extent. If the movements in the games or the challenges are based on measurements related to the ability to move, there will also be a possibility to follow progress via the use of the game [25].

Several guidelines suggest appropriate motor- and cognitive challenges [6]. The variation among the users in terms of ability is very large, both with respect to older adults in general and for users of a rehabilitation system. As shown in one of our studies [26], there was a need for a broad range of levels of difficulty and there was a need for exercises that were both possible to conduct both standing and sitting down. Finally, there is also a need for quite large amounts of content so that the games continue to be interesting for a longer period of time.

Environment.

According to Gamberini [15], when designing games for older adults, the content should be familiar and related to everyday life. The preference about content from everyday life was also shown in our own studies [26, 32]. This may be especially important with respect to physical rehabilitation games due to the need of practicing tasks that have become difficult to conduct after an injury.

Gamberini [15] also suggests non-political and non-violent games with, e.g. educational or historical content for games targeting towards older adults. To some extend this was in line with our experiences from developing tools for COPD patients. The users in our study preferred simple games with easy interaction instead of games with advanced graphics and in-game challenges [29, 30]. However, older adults are a heterogeneous group, and differences are oftentimes ignored [31]. Preferences and interests may vary within the user groups. Further, the aim with playing the games could have several other purposes, for example socializing with others such as children and grandchildren. In that case, the games need to consist of content and game features that do not contribute to that the older adult will be perceived as “old and boring”.

Several guidelines suggest engaging environments [6], and this is of course very important when the user has to exercise to a large extent to achieve progress in the rehabilitation. However, when developing exergames with limited resources, for example for rehabilitation, the expectations on the environment are still similar to other commercial games. This could lead to design decisions regarding meeting the intended outcome (efficient exercises) and at the same time deliver games that are appealing enough compared to games developed with tremendously more recourses.

Motivation and Gaming Mechanisms.

Guidelines place focus on the importance of engaging tasks, especially in games involving rehabilitation, since motivation can diminish rapidly [6] and high intensity training is needed. However, many general principals within game design and motivation are applicable for these kinds of games as well. The important aspect will be to apply them with different target groups in mind. A further aspect to take into consideration is personality and beliefs in getting results [25]. Games and tasks in the games need to be able to meet users with different approaches to their own ability to achieve progress. Based on insights from interviews with COPD patients, motivational aspects do not have to be in-game rewards or achievements. According to our experience, this user group appreciated and felt comfortable when the games provided the possibility to adapt to their own ability. Such features were said to reduce stress and created a motivating context in itself. The possibility for social interaction was also found very valuable and served in this case as a motivation to keep using the system.

Social Aspects.

The guidelines presented place an emphasis on the importance of social interaction. This was also shown in our studies, both with respect to the stroke rehabilitation system [25, 26] and the COPD system [29]. In both systems the users were able to use video communication for interacting with their physiotherapist. This was highly appreciated since it provided both the possibility to be seen and the possibility to get feedback on progress. It should also be noted that for many users the social aspect is the most important motivational feature. The positive aspects of this social interaction with care professionals or caregivers could also be taken further and be incorporated in the games in different ways that increase the motivation further [33].

Interaction and Feedback.

The literature suggests non-questionable features such as clear interfaces with a relevant amount of text that is easy to read and understand [14]. The guidelines also suggest appropriate and customizable feedback [6], which our studies have shown as well. Auditive feedback and sound should be optional since it for some users is disturbing. Based on insights from our studies, it could be a challenge to decide on when to provide feedback. There is no straightforward answer and it could vary between user groups and individuals. In some situations, tasks and exercises may need the user’s full attention and real-time feedback would just add too much complexity. In other situations, real time feedback could be very valuable, e.g. when exercising close to the person’s limit. A constant interaction/feedback about intensity and level could make it possible to push limits, but at the same time being able to slow down when necessary.

Another example of when real-time feedback could be useful is the representation of the body to a person with a very asymmetric posture. This could provide the user with feedback about existing posture and goals showing what to strive for. Rewards and other traditional gaming elements may in some cases need to be given real-time, in other cases later, depending on user and situation. However, this also touches upon the sensitive aspect to what extent the system should provide information about incorrect movements. In our stroke rehabilitation case, it was an appreciated feature by some of the users. However, it could also be discouraging to get this kind of feedback when lacking the ability to achieve the correct movement or posture.

Progress over time may not be necessary to be given during gaming, this could be given after training or together with a physiotherapist. This kind of feedback will also benefit from being related to everyday life and tasks that the person will be able to conduct [6, 12]. Feedback also needs to be adapted to the context of the user and his/her possibilities to improve. A person with possibilities to get better and to improve may benefit from challenges and awards related to better performance. A person with a disease, such as COPD where it is less likely that the person will be able to perform better, may benefit more from feedback of other kinds. For example, getting rewards for doing the exercises or being able to get social support from peers.

6 Conclusions

In this paper we present and categorize existing design guidelines with respect to exergames for older adults, physical rehabilitation purposes and for people with chronic diseases i.e. COPD and PD. Existing design guidelines are discussed and enrichened by own experiences from developing exergames in a number of different projects.

One important design aspect, that was present in most of the literature and with respect to all described target groups, was that the exercises should be adapted towards the user and the context. However, with respect to older adults and users with chronic diseases, the design recommendations placed a larger focus on taking into account initial age and disease related physical limitations. Design guidelines addressing rehabilitation games on the other hand, placed a larger focus on exercises to be appropriated for a specific injury and that they should provide high intensity interactions. Not surprisingly, since the aim with the rehabilitation is to achieve improvement, while in the case with older adults in general and chronic diseases the goal is generally to maintain abilities.

One important aim with exergames is that they should be used often and over a long period of time. To be able to achieve this, environments and content need to be fun and engaging. Further, the games have to provide a wide range of difficulty levels and a possibility to adjust the level based on the user’s ability or usage context. When designing feedback, it is also important to take into consideration the target group’s possibilities to actually achieve improvements. If it is not possible to increase performance, the games should not focus on scores and competition, instead feedback should focus on positive aspects of conduction the exercises on a frequent basis.

Practical aspects, such as space for the equipment in the home environment, should not be ignored. In our projects we have often faced the fact that this could limit, which exercises the users, can perform or which games they can play. From a design perspective, this needs to be taken into consideration both with respect to selection of hardware and of exercises/movements.

In this paper we have discussed the importance of how exergames are adjustable to different physical and cognitive needs or abilities. However, it is also important to avoid preconceptions about different target groups. For example, older adults are a heterogenic group with a variety of preferences and interests, and new generations of older adults may have little in common with the stereotypic picture of an older person of today. This will be important to keep in mind, both when making decisions about content for the games and when designing the interaction.

As users are very different from each other, it is important that the possibility to compete is optional. For some people competing may be their main motivation, while for others competing could be perceived as totally meaningless. With respect to this, it is also important to keep in mind that preferences related to competing may not be related to the target group per se, but rather other factors such as personality or background. It should also be noted that what motivates different users and user groups vary. For example, in several studies in the area, social aspects have been considered very valuable, and in some cases and for some users this has shown to be the main motivating feature of the game.

This paper has provided an overview of existing guidelines alongside with a contribution to the area in terms of the authors’ own insights. The main focus has been on a few number of intended target groups. However, it should be noted that exergames also could be valuable and useful to a much broader audience. Physical activity is important to all of us, and these games could provide a fun and engaging way to exercise. The costs for developing large amounts of gaming content and a variety of tasks could also be balanced by larger audiences and effective ways of developing the games.