Vibrations, Posture, and the Stabilization of Gaze: An Experimental Study on Impedance Control

Kredel, Ralf; Grimm, Adrian; Hossner, Ernst-Joachim (26 September 2013). Vibrations, Posture, and the Stabilization of Gaze: An Experimental Study on Impedance Control. In: 21. Sportwissenschaftlicher Hochschultag - Sportwissenschaft grenzenlos?! Schriften der Deutschen Vereinigung für Sportwissenschaft: Vol. 230 (p. 217). Feldhaus

Full text not available from this repository.

Vibrations, Posture, and the Stabilization of Gaze:
An Experimental Study on Impedance Control

R. KREDEL, A. GRIMM & E.-J. HOSSNER
University of Bern, Switzerland
Introduction
Franklin and Wolpert (2011) identify impedance control, i.e., the competence to resist changes in position, velocity or acceleration caused by environmental disturbances, as one of five computational mechanisms which allow for skilled and fluent sen-sorimotor behavior. Accordingly, impedance control is of particular interest in situa-tions in which the motor task exhibits unpredictable components as it is the case in downhill biking or downhill skiing. In an experimental study, the question is asked whether impedance control, beyond its benefits for motor control, also helps to stabi-lize gaze what, in turn, may be essential for maintaining other control mechanisms (e.g., the internal modeling of future states) in an optimal range.
Method
In a 3x2x4 within-subject ANOVA design, 72 participants conducted three tests on visual acuity and contrast (Landolt / Grating and Vernier) in two different postures (standing vs. squat) on a platform vibrating at four different frequencies (ZEPTOR; 0 Hz, 4 Hz, 8 Hz, 12 Hz; no random noise; constant amplitude) in a counterbalanced or-der with 1-minute breaks in-between. In addition, perceived exertion (Borg) was rated by participants after each condition.
Results
For Landolt and Grating, significant main effects for posture and frequency are re-vealed, representing lower acuity/contrast thresholds for standing and for higher fre-quencies in general, as well as a significant interaction (p < .05), standing for in-creasing posture differences with increasing frequencies. Overall, performance could be maintained at the 0 Hz/standing level up to a frequency of 8 Hz, if bending of the knees was allowed. The fact that this result is not only due to exertion is proved by the Borg ratings showing significant main effects only, i.e., higher exertion scores for standing and for higher frequencies, but no significant interaction (p > .40). The same pattern, although not significant, is revealed for the Vernier test.
Discussion
Apparently, postures improving impedance control not only turn out to help to resist disturbances but also assist in stabilizing gaze in spite of these perturbations. Con-sequently, studying the interaction of these control mechanisms in complex unpre-dictable environments seems to be a fruitful field of research for the future.

References
Franklin, D. W., & Wolpert, D. M. (2011). Computational mechanisms of sensorimotor control. Neuron, 72, 425-442.

Item Type:	Conference or Workshop Item (Paper)
Division/Institute:	07 Faculty of Human Sciences > Institute of Sport Science (ISPW) 07 Faculty of Human Sciences > Institute of Sport Science (ISPW) > Movement and Exercise Science
UniBE Contributor:	Kredel, Ralf, Hossner, Ernst-Joachim
Subjects:	700 Arts > 790 Sports, games & entertainment 600 Technology > 610 Medicine & health
ISBN:	978-3-88020-602-1
Series:	Schriften der Deutschen Vereinigung für Sportwissenschaft
Publisher:	Feldhaus
Language:	German
Submitter:	Ralf Kredel
Date Deposited:	13 Mar 2014 11:55
Last Modified:	05 Dec 2022 14:29
URI:	https://boris.unibe.ch/id/eprint/43156