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Locomotor Sensory Organization Test: How Sensory Conflict Affects the Temporal Structure of Sway Variability During Gait

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When maintaining postural stability temporally under increased sensory conflict, a more rigid response is used where the available degrees of freedom are essentially frozen. The current study investigated if such a strategy is also utilized during more dynamic situations of postural control as is the case with walking. This study attempted to answer this question by using the Locomotor Sensory Organization Test (LSOT). This apparatus incorporates SOT inspired perturbations of the visual and the somatosensory system. Ten healthy young adults performed the six conditions of the traditional SOT and the corresponding six conditions on the LSOT. The temporal structure of sway variability was evaluated from all conditions. The results showed that in the anterior posterior direction somatosensory input is crucial for postural control for both walking and standing; visual input also had an effect but was not as prominent as the somatosensory input. In the medial lateral direction and with respect to walking, visual input has a much larger effect than somatosensory input. This is possibly due to the added contributions by peripheral vision during walking; in standing such contributions may not be as significant for postural control. In sum, as sensory conflict increases more rigid and regular sway patterns are found during standing confirming the previous results presented in the literature, however the opposite was the case with walking where more exploratory and adaptive movement patterns are present.

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This work was supported by the Center for Research in Human Movement Variability of the University of Nebraska Omaha and the NIH (P20GM109090 and R01AG034995). Additional support was provided by NASA EPSCoR NNX11AM06A. We specially thank for authors from the previous publication (Jung Hung Chien, Diderik-Jan Anthony Eikema, Mukul Mukherjee, and Nicholas Stergiou, Annual of Biomechanics of Engineering, 2014) to allow us to modify several figures.

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Correspondence to Nicholas Stergiou.

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Associate Editor Thurmon E. Lockhart oversaw the review of this article.

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Chien, J.H., Mukherjee, M., Siu, KC. et al. Locomotor Sensory Organization Test: How Sensory Conflict Affects the Temporal Structure of Sway Variability During Gait. Ann Biomed Eng 44, 1625–1635 (2016).

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