Postural indicators of arousal level while sitting without trunk support

Abstract

Background: Patients with disorders of consciousness show electroencephalogram signs of low arousal and decreased cerebral activity resembling sleep in healthy individuals. Further, activities of wakefulness are not necessarily associated with awareness. Sitting without trunk support may improve arousal and several other physiological parameters in patients with disorders of consciousness patients, which may in turn provide a foundation for improved nursing care and further interventions to relearn activities of independent living. Aims: This study examined the relationship between arousal and posture in a healthy cohort to identify postural changes indicative of arousal level. Methods: Thirty healthy volunteers sat on a bench with markers affixed to six points on the upper body for monitoring sagittal posture. Subjects fell asleep and woke spontaneously while sitting, and their posture was analyzed for two-dimensional motion. The state of arousal was confirmed using a simple electroencephalograph of frontal lobe activity. Results: When arousal declined, sitting posture on the sagittal plane, the head, neck, and upper trunk were anteverted. Conclusion: The angles of the head, neck and upper trunk on the sagittal plane can be used as an index of low arousal in uncommunicative patients with disorders of consciousness patients to aid in nursing care.