Title of Document : POSTURAL COORDINATION PATTERNS : VISUAL ROTATION AND TRANSLATION

Title of Document: POSTURAL COORDINATION PATTERNS: VISUAL ROTATION AND TRANSLATION Yuanfen Zhang, MA, 2006 Directed By: Professor John Jeka, Department of Kinesiology Recent studies have shown co-existing trunk-leg coordination patterns during quiet stance: in-phase and anti-phase for frequencies below and above 1 Hz, respectively. Two experiments investigated whether the nervous system assumes a multilinked internal model in sensory coupling? In the first experiment, we investigated the influence of the addition or removal of sensory information on these patterns. Trunk-leg coherence decreased with the addition of static vision and light touch, in the AP and ML directions, respectively, at frequencies below 1 Hz, suggesting the in-phase pattern may be more affected by neural control than the antiphase pattern. In the second experiment, we compared translation of the visual field to a rotation relative to the ankle/hip. Gain and phase between the trunk/leg angles relative to the visual display showed only minor condition differences. The overall results suggest the nervous system adopts a simple control strategy of a single-link internal model at low frequencies. POSTURAL COORDINATION PATTERNS: VISUAL ROTATION AND TRANSLATION