Office workers are familiar with carpal tunnel, stiff shoulders and eye-strain headaches -- all well-known side effects of prolonged computer use. But what about new technologies like virtual reality (VR), which is increasingly being used for education and industrial training? How does using VR affect our joints and muscles?
To find out, researchers at Northern Illinois University and Oregon State University (OSU) assessed how some common VR movements contribute to muscle strain and discomfort.
Unlike conventional computer users, where a desk or the arms of a chair offer some level of support for the hands and arms, VR users wear a headset and engage in full-body, three-dimensional movements.
"There are no standards and guidelines for virtual and augmented reality interactions," said researcher Jay Kim of OSU'S College of Public Health and Human Sciences. "We wanted to evaluate the effects of the target distances, locations and sizes so we can better design these interfaces to reduce the risk for potential musculoskeletal injuries."
For the study, the researchers used motion capture to record participants' movements and electromyography to measure electrical activity in their muscles. The tests were repeated with the visuals placed at eye level, 15 degrees above eye level, 15 degrees below eye level and 30 degrees below eye level.
Regardless of the angle, extending the arm straight out caused shoulder discomfort in as little as three minutes, the study showed. With prolonged use, this may lead to health problems like 'gorilla arm syndrome' and rotator cuff injuries.
In addition, the heavy VR headset may increase the burden on the cervical spine, risking greater neck strain.
"Based on this study, we recommend that objects that are being interacted with more often should be closer to the body," Kim said. "And objects should be located at eye level, rather than up and down."
The findings have been published in Applied Ergonomics.