## 1 Introduction  
Postural stability plays an important role in our daily lives, and the ability to maintain one's balance relies upon complex physiological processes. Postural control involves a variety of sensory inputs, including proprioceptive, vestibular, visual, and tactile somatosensory inputs. The body state, or body schema, is represented by the integration of these multisensory inputs, and is then employed by the brain in the generation of motion [1]. More specifically, the combined activities and effects of the motor nervous system, sensory nervous system, cognitive ability, and visual feedback are typically needed to maintain postural balance. As such, if one of those contributing systems is defective, balance may be adversely affected, even to the extent that falls occur. [PERSON] proposed that postural stability is an essential and indispensable physical capability in our daily lives [2]. Relatedly, physical fitness can be built up by regular and long-term exercise, and exercise can improve postural stability in a manner that may help prevent falls [3,4]. Falls are caused by many factors. Among the factors that are commonly responsible for falls are balance problems; gait problems; musculoskeletal problems; neurological problems; the utilization of medicines that affect balance; memory, thinking, and visual impairments; and environmental hazards (such as slippery floors, stairs, and poor lighting) [5]. Hemiparesis is the most frequent occurring neurological deficit after strokes [6]. Hemiparetis stroke patients often present with balance deficits, which in turn means that hemiparetic stroke patients have a very high risk of falls [7]. A study by [PERSON] et al. [8] reported that 73% of stroke patients had at least one fall within the first six months after a stroke, that 21% had at least one fall more than six months after, and that over half of all the reported falls occurred during walking activities due to problems such as loss of balance, misjudgments, and foot dragging. Fear of falling also leads to increased dependence of stroke patients on caregivers and reduced self-care skills in daily life [9]. In order to prevent and reduce the risk of falls, stroke rehabilitation provides a series of treatments aimed at helping stroke patients to relearn skills lost due to the effects of stroke on different parts of their brains. In the last few decades, rehabilitation has become an increasingly significant element in stroke care [10]. Various rehabilitation strategies are established or in development, targeting muscle activity, postural, and gait tasks. These include neuro-facilitation approaches, muscle strength training, treadmill training, multisensory training, and aerobic exercise training. Some strategies use technological equipment, such as functional electrical stimulation (FES) and electromechanical or robot-assisted gait training [11]. However, the physical rehabilitation and general fitness training regimens in rehabilitation centers were too routine and usually considered by patients to be tedious and monotonous, leading to reduced patient motivation, reduced compliance, and reduced effectiveness. In recent years, however, the use of virtual reality (VR) has been introduced in the field of stroke rehabilitation [12]. It has been shown that VR training can improve upper extremity motor function in adults with chronic hemiparesis resulting from a stroke [13]. For example, [PERSON] et al. found that a positive and promising effect of VR training on balance and gait ability can be expected [14]. Meanwhile, [PERSON] made another important contribution to rehabilitation efforts through the development of modular interactive tiles(r) (MTs) [15]. The MTs for rehabilitation are designed to motivate patients to perform specific physical actions by creating playful experiences for them.