## 1 Introduction
The European regulatory framework requires a robotic device to be registered as a medical device used for rehabilitation purposes. This requirement is ensured by the CE mark that allows its inclusion in the European Union market. Obtaining the CE mark ensures the fulfilment of European standards on quality and safety. As regards the US market, the Center for Devices and Radiological Health (CDRH) within the Food and Drug Administration is responsible for medical devices regulations and their sale in the United States. Robots for rehabilitation have some relevant features that make them potentially relevant in the rehabilitation of children with neurological diseases. Firstly, the combination of robotic tasks with virtual reality environments provides an enriched experience that fosters higher focus and attention, novelty, fun, and challenge, which, together, maximize cognitive engagement, thus stimulating the child's active voluntary participation and, most importantly, neuroplasticity [14]. Secondly, different feedback modalities of the patient's performance, like auditive, visual and haptic, can enrich the treatment, fostering sensorimotor learning. In addition, an educational effort of healthcare professionals involved in the rehabilitation process should be put forward to improve knowledge on the specific technical features of these devices. The market offers many types of robots, and their technical characteristics are often not accompanied by specific clinical indications about the target functions, affecting, in turn, the development of the individualized neuro rehabilitation program [15]. On one hand, the relentless technical innovation allows the creation of complex and sophisticated devices for neurological rehabilitation [16; 17]. On the other hand, the lack of beneficial dialogue between developers and users limits the use of these devices in clinical practice [18]. Based on these considerations, it is conceivable that robot-assisted rehabilitation can be successfully applied to rehabilitation in children affected by neurological disorders. However, most of the literature on this topic is focused on adults, and further effort is needed to provide evidence on the developmental age [12; 19]. Recently, a review was carried out on robotic devices for upper limb rehabilitation in children with neurological impairments [19]. The study presented an overview of the upper limb robotic device's characteristics, their applications in the clinical setting, and results. However, to the best of our knowledge a similar study on gait and balance rehabilitation has not been published yet. [PERSON] and colleagues [19] have pointed out that optimal control strategies and sensory-motor recovery in children with neurological diseases have not been defined yet. Moreover, rehabilitation protocols in this domain should be more detailed on specific contents and applications [12]. Most of the literature on this topic has focused on the type of device used to overlook treatment modalities. However, understanding the effects of different training modalities using robotic devices is crucial for improving rehabilitation care. It can foster the spread of these devices in the context of children's rehabilitation. This systematic review aims to provide an overview of the existing literature on robots and electromechanical devices used for the rehabilitation of gait and balance in children with neurological disability and their rehabilitation application, focusing on the type of robotic devices used and their application protocols. A comprehensive perspective on the main results achieved by applying robot-assisted rehabilitation, which are the most successful methodologies implemented from which to lay the foundations for future studies on robot-based approaches, is provided.