# Detection of Movement Intention for Operating Methods of Serious Games
###### Abstract  
In many post-stroke cases, patients show dysfunctions in movement, cognition, sense, and language, depending on the damaged area of the brain. Active and repetitive physical rehabilitation centered on the stroke-affected side is essential for effective and rapid neurological recovery of upper extremity dysfunction due to hemiplegia. A symmetric upper extremity trainer is utilized to assist the patient body, depending upon the degree of hemiplegia. In this study, we developed a novel balance handle as a symmetric upper extremity trainer capable of extension, flexion, pronation, and supination of the upper extremity. We collected the surface electromyogram (sEMG) signal data while the subjects were playing a serious game and recorded the electroencephalogram (EEG) signal data while the subjects were performing basic movements with the balance handle, to analyze the effectiveness of the device as an assistive tool for rehabilitation. The triceps brachii were activated during the extension movements, whereas the biceps brachii and deltoid muscles were activated during the flexion movements. With the balance handle, the peak event-related desynchronization (ERD) values were relatively lower while showing higher peak event-related synchronization (ERS) values compared to other types of operating methods, such as hand gripping and gamepad operation. Movement intention of tilting the balance handle for the \(\alpha\) and \(\beta\) waves was clearly distinguished from the other tasks. These data demonstrated the potential of various applications using the developed proof-of-concept upper extremity trainer to bring out an excellent rehabilitative effect not only through muscle growth but also via identification of large movement intentions inducing brain activation exercise. bilateral movement training; event-related desynchronization; hemiplegia; serious game; symmetric upper extremity trainer +
Footnote †: 2021: 15 January 2021  
the stroke-affected side is essential for effective and rapid neurological recovery of upper extremity dysfunction due to hemipleggia [6]. The methods to improve the stroke-affected movement functions of the upper extremity include constraint-induced movement therapy, rehabilitation robotics, mirror therapy, and bilateral movement training [7; 8; 9]. Specifically, the bilateral movement training utilizes substitution, in which the neural network of the healthy side compensates for the functions of the neural network of the stroke-affected side by simultaneously activating the neural networks of both the healthy and pathologic sides [10]. In general, a symmetric upper extremity trainer is utilized to assist the patient body, depending upon the degree of hemipleggia. Recent studies have attempted to associate the rehabilitation equipment used to improve or treat physical abilities with serious games, applying game elements such as fun and challenge. Such programs are considered to increase the patients' intention to rehabilitate and effectively recovers the physical abilities by reducing the rejection or boredom of treatment that patients may have [11]. Moreover, it can help users actively perform steady repetitive exercises, which are the most important in rehabilitation, by offering them a sense of reality beyond the limited user interface of the serious games, consisting of a keyboard, mouse, and specific buttons and sticks [12; 13]. In this study, a novel balance handle was manufactured as a symmetric upper extremity trainer to enable bilateral rehabilitation movements, such as extension, flexion, pronation, and supination of the upper extremity. The balance handle was connected to a serious game, and a surface electromyogram (sEMG) was measured for the triceps brachii, biceps brachii, and deltoid to assess the muscular activation while the users played the game.