0-1 Hz Oscillations In Postural Sway Scale Differentially With Sensory Weighting In Young Adults

Postural sway is predominantly maintained using three primary sensory input systems: vision, proprioception/somatosensory, and vestibulum. The modified Clinical Test of Sensory Interaction in Balance (mCTSIB) is used to determine an individual's dependence on all sensory systems (vision, vestibular, and somatosensory). It can also be used as balance training/rehabilitation, providing multiple conditions that challenge the sensory feedback system needed to maintain balance. Recent evidence suggests that low-frequency oscillations in postural sway from 0-1 Hz may contain information regarding the individual contributions of these senses to maintaining balance. PURPOSE: To determine how the vision, proprioception, and vestibular senses interact and contribute to postural sway oscillations from 0-1 Hz. METHODS: We tested a hundred healthy young adults (50 males and 50 females) between ages of 18 and 30 years old (21 ± 3 years). Each subject was tested under four conditions on a portable force plate: 1) Quiet standing with eyes open - on a firm surface (standard); 2) Quiet standing with eyes closed (somatosensory); 3) Quiet standing with eyes open on a foam cushion (visual), and 4) Quiet standing with eyes closed on a foam cushion (vestibular). RESULTS: Center of Pressure (F = 350.85, p < .001, η2 = .782), anterior-posterior (F = 145.367, p < .001, η2 = .820), mediolateral (F = 49.601, p < .001, η2 = .608) sway path lengths were significantly different across conditions (standard < visual < somatosensory < vestibular). The power spectral density of 0-1 Hz oscillations similarly scaled from standard < visual < somatosensory < vestibular conditions and were significantly different across test conditions (F = 58.949, p < .001, η2 = .559). CONCLUSION: Our findings suggest that the sensory interaction in balance as tested by the mCTSIB on a force plate is useful to determine the relative contribution and interaction of multiple senses in maintaining balance.