## 1 Introduction
Although there are some very advanced commercial exergames, they may not be suitable for use in rehabilitation tasks [16], since they do not generally take into account the particularities and clinical needs of the users with motor limitations [17]. Most of the conducted research has been oriented towards the development of specific systems for groups of patients with very specific characteristics (e.g., cerebral palsy), being also related to adults or elderly patients [11; 12; 18; 19]. However, one of the groups that may benefit most from systems that make use of devices previously mentioned is the group of younger patients (children and adolescents), who are familiar with its use and often have some of them at home. There are some examples of rehabilitation approaches that make use of these devices. In [16], a Kinect-based system is presented for the rehabilitation of upper limbs in children affected by Friedreich's Ataxia. A system using Leap Motion for the rehabilitation of children affected by cerebral palsy is described in [20], and in [21] this same device is used to establish an environment that enhances children's motor skills. A system that employed the commercial Wii Fit game for the rehabilitation of adolescents with arthritis is shown in [22]. There are systems that combine some of these devices, as in [23], where the Kinect and the Nintendo Wii are used to evaluate the oscillation of the body in children with cerebral palsy. In the field of rehabilitation of young patients, as already mentioned, motivation plays a key role. Therefore, the introduction of gamification techniques in rehabilitation software can provide great benefits [10]. There are some examples of systems in this line of work. In this context, [PERSON] et al. [24] describes a virtual reality environment in which children rehabilitate their motor functions blowing virtual bubbles on a monitor with their hands. In [25], adolescents are motivated by simulating everyday activities, which are replicated by a virtual avatar. However, one of the main drawbacks of the serious systems and kits available in the literature is their specificity, i.e., they are usually based on patients with very specific types of injuries or motor problems. Therefore, it would be ideal that the great efforts invested in the development of the rehabilitation system lead to the adaptation of the exercises according both to the patients' disease and their needs. This issue has been addressed through proposals for user-centered systems design [26] and methodologies for designing efficient and safe therapeutic exergames [27]. Besides, a very promising line of research has recently emerged, which advocates the combination of personalization and automatic generation of exergames. This approach offers the therapist greater possibilities of personalization and adaptation when defining the exercise routine to be followed at home by each specific patient. In this line of work, the system StoryTec [28] stands out, which applies the concept of a narrative story so that experts without knowledge of Information and Communication Technologies (ICT) can develop their own games using an editor. [PERSON] et al. presents TANGO:H [29], a platform that includes a graphic tool for professionals to create games adapted to the needs of their patients. In contrast, in Theraplay [30] the therapist personalizes the exercises by recording movements and postures according to the patient's limitations. Then, a 3D avatar plays them back to help patients follow the exercises. In this paper we present a systematic mapping study (SMS) of the main works that have addressed the problems mentioned above. The selected articles were analyzed according to several characteristics based on three fundamental aspects about the rehabilitation system: its use by the patient, its use by the therapist, and its gamification support, as a key factor for motivating young patients.