## 4 Conclusions and Future Work  
The use of virtual systems for physical rehabilitation is a field of growing interest, in which a large number of contributions have been made in recent years. However, most of the existing developments are aimed at elderly people and patients with specific pathologies. Our interest is focused on the rehabilitation of a particular group, young patients (children and adolescents), in whom the lack of motivation and the risk of dropping out of treatment are greater. It is considered that the use of gamification techniques in rehabilitation software may partly mitigate this problem. On the other hand, since the patient's pathologies can be varied, it is also of interest that exergames and exercise routines may be defined by the therapist and adapted to the particularities of each patient and specific pathologies. In order to have a better knowledge of the current state of this area, a systematic mapping study has been carried out. This analysis indicates that most of the published articles describe systems that allow the patient to work autonomously at home, which are mostly based on asynchronous communication with the specialist. Moreover, they support a natural interaction (air-based) thanks to the use of generic and widely used gaming devices among young people, such as _Microsoft Kinect_, _Nintendo Wii mote_, or _Leap motion_. It is necessary to emphasize that there are few works that support the automatic generation of exergames and the personalization of the game features for the patients, and even fewer that propose some kind of methodology to be followed in the development or use of exergames. The conclusions drawn from the mapping study have served to improve an existing software prototype for home rehabilitation. Thus, and in relation to the feedback received by the patient, this can be instant and provided by the application, or deferred and performed by the therapist. To better support asynchronous communication with the specialist, a set of metrics and performance indicators have been incorporated to the system. Regarding to the interaction style between the user and the application, the use of voice commands have been added, which allow a more natural communication, especially for patients with some severe movement limitation. A noteworthy and differentiating feature of the current proposal is the support for the personalization of exercise routines, as well as the automatic generation of exergames, which is carried out in the context of a co-creative methodological proposal among the different stakeholders involved in rehabilitation therapy. The present work opens a series of working lines that are expected to continue advancing with the research. On the one hand, it is necessary to deepen and incorporate to the developed system more gamification mechanisms, such as daily or weekly challenges. We also want to improve and expand the type and amount of information that the system provides to the therapist, for subsequent analysis and decision making. In this sense, we are working in conjunction with rehabilitation specialists and physiotherapists to define new metrics and parameters that are considered appropriate and necessary to record with the aim of including in the system. Another improvement to be integrated consists in extending the proposed exergame specification language. Moreover, it would be ideal that the system, once installed in the patient's home, may be calibrated and customized based on the previous and current patient's performance. We are working on this as well. Finally, and as the developed framework evolves, formative and summative evaluations of the system will be carried out, involving both experts in the area and end users. Conceptualization, C.G.-P. and D.V. ; methodology, C.G.-P., C.L., and A.I.M. ; software, C.G.-P.; validation, C.L., A.I.M., and D.V. ; investigation, C.G.-P. and D.V. ; visualization, C.G.-P.; writing--original draft preparation, C.G.-P. and C.L. ; writing--review and editing, C.L., D.V., and A.I.M. ; supervision, D.V.