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Evaluation of Hologram Distances in Reducing Shoulder Stress During Augmented Reality Interactions

This study investigated the effect of different hologram distances on the shoulder postures, muscle activities, and the task performance (speed) during Augmented Reality (AR) interactions. With a repeated- measures design, 20 participants (10 males) performed the 3-D cube task involving gaze, pinching, and dragging gestures by different hologram distances: near (30 cm), middle (60 cm), and far (90 cm) relative to the participant. Meanwhile, muscle activities (upper trapezius, anterior and middle deltoid) and the right shoulder postures were measured. The results showed that hologram distances significantly affected middle deltoid muscle activities and shoulder flexion and abduction angles, and task performance during 3-D cube task (p’s < 0.001). The far hologram distance resulted in higher middle deltoid muscle activity and shoulder angles compared to the near and middle distances. Task performance was higher when the hologram was displayed in the middle compared to the near and far distances (p’s < 0.001). These results indicate that a hologram distance may be an important design factor affecting users’ shoulder stress and task performance during AR interactions.