The effect of wearing a head-mounted display on the boundaries of the cervical range of motion based on perceived comfort in a static posture

The head-mounted display (HMD) for virtual reality (VR) systems is becoming more popular due to technological advancements, providing users with a more immersive experience. Since an HMD is a wearable device, head movement may be restricted, compared to situations in which an HMD is not worn, and perceived discomfort during head movement may increase. Thus, this study recruited 30 participants and investigated the effects on perceived comfort from wearing an HMD, considering the cervical range of motion (CROM) in four head movement directions (flexion, extension, lateral bending, and rotation). We propose angle boundaries for joint isocomfort in order to evaluate the appropriateness of working postures in an HMD-based VR environment. Although the maximum CROM for head movement in all directions was not significantly limited by wearing the HMD, the main effects of wearing HMD on perceived discomfort were observed from extension and lateral bending. Based on the perceived CROM comfort score, appropriate ranges for each head movement direction are proposed. This study contributes to the establishment of ergonomic guidelines on the use of HMDs and the development of VR content.