In this study, a four-axis platform capable of rolling, pitch, and yaw rotation was created for rehabilitation and exercise. Based on this, a virtual coach and a virtual reality game system were developed. The virtual coach is a 3D person model created with the Unity program that allows the user to exercise in the correct posture with the virtual coach, and recognizes the correct posture with the Kinect. Additionally, a virtual reality game has been developed, and in conjunction with this, the actual platform also moves to increase the rehabilitation effect. The upper body and lower body movement and plantar pressure measurement were used to associate with the four-axis platform to maintain strength and balance the body.

We investigated fatigue in the erector spinae, upper trapezius muscles and changes in the cervical flexion-extension angle when individuals watched 360° videos, general videos using virtual reality (VR), and smartphones. The subjects included 34 young, healthy, South Korean college students. The systems VR Gear3, the Galaxy S8, and “STAR WARS 360 VR” made by the manufacturer Cube CZ were utilized. The subject test conditions were: 1) watching 360° video with VR (V360), 2) watching 360° video on a smartphone (S360), 3) watching general video with VR (VG), 4) and watching general video on a smartphone (SG). The subjects watched a video for 10 min under each condition, where median frequencies of the erector spinae and upper trapezius muscles were measured using electromyography, while changes in the cervical flexionextension angle were measured with an electrogoniometer. The results noted that the erector spinae and upper trapezius muscles were significantly fatigued over time in all conditions, with significant differences relating to time and conditional effect. Watching 360° videos was less fatiguing than watching general videos and neck muscles moved the most when watching V360, and least watching general videos. These results suggest that neck muscles are less fatigued when watching 360° videos.