Using Accelerometers to Record Postural Sway in Adolescents With Concussion: A Cross-Sectional Study.

Abstract

To investigate the magnitude of postural sway induced by different balance tasks in adolescents with concussion and to examine the associations of postural sway with concussion symptoms. Cross-sectional study. Fifty-six adolescents (20 girls, 36 boys) between 13 and 17 years of age who sustained a concussion within the past 44 days and were still symptomatic. Anterior-posterior postural sway was measured using an accelerometer attached to the participant's lower back while he or she performed 6 static-balance tasks that varied the visual input, type of surface, and foot stance. Participants self-reported symptoms that occurred at the time of the concussion (eg, dizziness, confusion, amnesia) as well as at the time of balance testing (eg, eye and head movement-induced dizziness). The normalized path length of postural sway during the different balance tasks was greater with the eyes closed (mean = 19.3 mG/s) compared with the eyes open (mean = 12.4 mG/s; P < .001). Furthermore, sway while standing with the feet together on a foam surface (mean = 17.9 mG/s) or while tandem standing on a firm surface (mean = 19.4 mG/s) was greater than sway while standing with the feet together on a firm surface (mean = 10.3 mG/s; P < .001). Greater sway was associated with dizziness and confusion reported at the time of injury ( P < .05). Dizziness and headache symptoms at rest were positively correlated with sway ( P < .05). Using accelerometers to measure postural sway during different challenging balance conditions in adolescents with concussion may provide an objective means of quantifying balance impairments in clinical environments. Furthermore, the association of these measurements with symptoms suggests a need to account for symptom severity at the time of testing.