Abstract:
"It is well established that sustained improper or poor head and neck posture is linked to degenerative musculoskeletal disorders, pain and dysfunction. Identified risk factors include gaze angle, head tilt, and forward head posture. This study investigates if alteration in field of view by restricting either the upper or lower field of view may provide beneficial effects by improving the aforementioned postural angles. Thirty-eight healthy participants were exposed to 9 testing conditions, which are the combination of 3 video display unit heights (30cm above, equal to, and 30cm below the eye level) and 3 modifications to the field of view (top-blocked, clear, and bottom-blocked non-magnifying glasses). Gaze angle, head tilt angle, neck angle, and trunk angle were assessed using reflective markers under each testing condition. Perceived exertion at the eyes, neck, and back, overall feeling of stress and discomfort, as well as bilateral muscle activity at the cervical erector spinae, upper trapezius, lumbar erector spinae, and sternocleidomastoid, were also collected. We found that modification to the field of view was capable of altering the gaze angle, head tilt, and neck angle significantly, but had varying effects on perceived exertion, stress, discomfort, and muscle activity. The results of our study suggest further investigation into the potential benefits of using glasses that restrict the upper field of view in environments with usage of visual display units placed significantly below eye level. This is significant because of increasing usage of phones, tablets and laptops in daily life and the associated detrimental effects that may have on posture and health."