# Haptic-Enabled Hand Rehabilitation in Stroke Patients: A Scoping Review
## 4 Discussion  
This paper aimed to (i) portray existing haptic-enabled hand rehabilitation in stroke patients, (ii) to map the use of haptic technology to support technology-assisted therapeutic interventions, and (iii) to investigate the effects of haptic-enabled interventions on motor and functional recovery in patients with stroke. The results revealed that literature on the topics is recent, small and sparse, as shown in Figures 2 and 3. The literature on the use of haptics as a technology to support hand therapy spanned over the two last decades, and articles are published first in North America than in Europe and Asia. Most of the studies involved a low number of participants and may include methodological biases as only 17% of the studies were randomized controlled trials. Lack of randomized clinical trials involved the last trend in health technologies is expected as, historically, most of the innovations are evaluated as part proof-of-concept and feasibility studies involving a tiny group of participants. The successful technologies get marketed speedily, and the conduction of randomized controlled trials may be expensive and complicated to run in some legislations. Developers may lean toward trusting real-world evidence elaborated  
Figure 5: Outcomes according to number of technologies involved. Figure 6: Outcomes classified according to intervention modality and the ICF framework components and domain according to intervention modality. throughout the post-commercialization phase rather than waiting for randomized controlled trial outcomes. Haptics is a technology that is increasingly integrated into hand rehabilitation, and it is used in combinations with up to three technologies: robotics and/or virtual reality and/or gaming. Robots are a technology that helps stroke patients move their limbs during practice so that clinicians save time and effort when treating patients and increasing the amount of therapy for each patient [77,78]. Virtual reality is a technology used successfully with stroke patients and other conditions such as Parkinson's disease [79] to create an interactive virtual world to fully immerse the patient in sensory and virtual feedback environments [80]. Virtual reality has been recommended to improve upper limb rehabilitation as an alternative that is more motivational and cost-effective than traditional care, mainly used for stroke patients. However, this field of investigation requires more research in terms of feasibility and usefulness in the telerehabilitation model with other neurological conditions [80,81]. Video games or console-based therapy are also used in rehabilitation, and its introduction offers results comparable to conventional therapy [82]. Haptic technology is a technology used to emulate the sense of touch by applying forces to the user and provide kinesthetic and tactile stimulation. Haptics can be used in virtual reality, augmented reality, rehabilitation robots and exoskeletons [83] to enhance the patient experience. Studies have shown that haptic technologies' sense of touch is essential for dexterity and manipulating objects involving fine motor skills, which could not be stimulated without haptic devices [40,41]. This review explored the effect of using haptics in combination with different technologies on hand rehabilitation outcomes hypothesizing that the more different technologies are combined with the haptics, the better the therapeutic outcomes. This review revealed that using three or four different technologies showed more positive outcomes than using two technologies (only one technology + haptic device/component). In particular, when normalized in the percentage of outcomes, combining three technologies presented more positive rehabilitation outcomes and less negative outcomes than combining haptics with one other technology or with three other technologies. The most cited combinations of three technologies identified in this study were \"robotics and virtual reality and haptics\" represented by 13 studies representing 32% of the studies.