Influenza dell'optic flow sul controllo posturale

Persiani, Michela (2015) Influenza dell'optic flow sul controllo posturale, [Dissertation thesis], Alma Mater Studiorum Università di Bologna. Dottorato di ricerca in Scienze farmacologiche e tossicologiche, dello sviluppo e del movimento umano, 27 Ciclo. DOI 10.6092/unibo/amsdottorato/7009.
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The study of optic flow on postural control may explain how self-motion perception contributes to postural stability in young males and females and how such function changes in the old falls risk population. Study I: The aim was to examine the optic flow effect on postural control in young people (n=24), using stabilometry and surface-electromyography. Subjects viewed expansion and contraction optic flow stimuli which were presented full field, in the foveral or in the peripheral visual field. Results showed that optic flow stimulation causes an asymmetry in postural balance and a different lateralization of postural control in men and women. Gender differences evoked by optic flow were found both in the muscle activity and in the prevalent direction of oscillation. The COP spatial variability was reduced during the view of peripheral stimuli which evoked a clustered prevalent direction of oscillation, while foveal and random stimuli induced non-distributed directions. Study II was aimed at investigating the age-related mechanisms of postural stability during the view of optic flow stimuli in young (n=17) and old (n=19) people, using stabilometry and kinematic. Results showed that old people showed a greater effort to maintain posture during the view of optic flow stimuli than the young. Elderly seems to use the head stabilization on trunk strategy. Visual stimuli evoke an excitatory input on postural muscles, but the stimulus structure produces different postural effects. Peripheral optic flow stabilizes postural sway, while random and foveal stimuli provoke larger sway variability similar to those evoked in baseline. Postural control uses different mechanisms within each leg to produce the appropriate postural response to interact with extrapersonal environment. Ageing reduce the effortlessness to stabilize posture during optic flow, suggesting a neuronal processing decline associated with difficulty integrating multi-sensory information of self-motion perception and increasing risk of falls.

Tipologia del documento
Tesi di dottorato
Persiani, Michela
Dottorato di ricerca
Scuola di dottorato
Scienze biologiche, biomediche e biotecnologiche
Settore disciplinare
Settore concorsuale
Parole chiave
Optic flow, Postural Control, Visual System, Electromyography, Force Platform, Motion Capture System, Biomechanics, Gender Differences, Old people, Falls Risk, Falls, Physiological Profile Assessment (PPA), Postural Strategies,
Data di discussione
14 Aprile 2015

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