Current Search: Forelimb (x)
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Title
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The coordination dynamics of single limb multijoint movement patterns: Spatial bifurcations and hysteresis.
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Creator
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Buchanan, John J., Florida Atlantic University, Kelso, J. A. Scott
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Abstract/Description
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The aim of this research was to study the coordinative dynamics of multijoint arm movements as a function of forearm spatial orientation. Six subjects rhythmically coordinated flexion and extension of the right elbow and wrist under the following conditions: (1) forearm supine: wrist flexion/elbow flexion and vice versa; and (2) forearm prone: wrist flexion/elbow extension and vice versa. Starting in either pattern, subjects rotated the forearm in eight 20 steps, producing 15 cycles of motion...
Show moreThe aim of this research was to study the coordinative dynamics of multijoint arm movements as a function of forearm spatial orientation. Six subjects rhythmically coordinated flexion and extension of the right elbow and wrist under the following conditions: (1) forearm supine: wrist flexion/elbow flexion and vice versa; and (2) forearm prone: wrist flexion/elbow extension and vice versa. Starting in either pattern, subjects rotated the forearm in eight 20 steps, producing 15 cycles of motion at a frequency of 1.25 Hz. Switching from pattern (1) to pattern (2) and vice versa was observed at a critical spatial orientation. The critical point depended on the direction of forearm rotation, thus revealing the hysteretic nature of the switching. En route to the transition, regardless of direction of change, critical fluctuations and critical slowing down were observed in the relative phasing between the joints. Such results provide definitive evidence that relative phase is a viable order parameter, spatial orientation a relevant control parameter and loss of stability the chief mechanism leading to observed changes in coordination.
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Date Issued
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1992
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PURL
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http://purl.flvc.org/fcla/dt/14806
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Subject Headings
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Arm, Forelimb, Human mechanics, Kinesiology
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Format
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Document (PDF)
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Title
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Bereitschaftspotentials and the frequency and phase characteristics of the EEG preceding bimanual finger movements.
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Creator
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Wallenstein, Gene Vincent, Florida Atlantic University, Nash, Allan J.
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Abstract/Description
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A delayed response paradigm was used to investigate the cerebral electroencephalographic (EEG) signal preceding bimanual finger flexions of continuously increasing and decreasing movement rates. The Bereitschaftspotential displayed larger amplitudes at faster required response rates as did two spectral frequency modes, which also showed magnitude reversals depending on the initiating finger. Furthermore, at these specific frequency modes, the averaged relative phase between electrode...
Show moreA delayed response paradigm was used to investigate the cerebral electroencephalographic (EEG) signal preceding bimanual finger flexions of continuously increasing and decreasing movement rates. The Bereitschaftspotential displayed larger amplitudes at faster required response rates as did two spectral frequency modes, which also showed magnitude reversals depending on the initiating finger. Furthermore, at these specific frequency modes, the averaged relative phase between electrode locations C3 and C4, as well as the variance in this measure was found to correspond closely to the variance in inter-response times derived from the subjects' movements. The results suggest the existence of possible signatures on the neurophysiological level which may yield information regarding the efficacy and parametric properties of the impending movement.
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Date Issued
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1992
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PURL
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http://purl.flvc.org/fcla/dt/14847
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Subject Headings
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Electroencephalography, Arm, Forelimb, Human mechanics, Neurophysiology
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Format
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Document (PDF)
