Author Type

Graduate Student

Date of Award

1992

Document Type

Thesis

Publication Status

Version of Record

Submission Date

October 2026

Thesis/Dissertation Advisor [Chair]

Kelso, J. A. Scott

Abstract

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 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.

Extent

77 p.

Comments

Charles E. Schmidt College of Science|Thesis (M.A.)--Florida Atlantic University, 1992.|FAU Electronic Theses and Dissertations Collection|Charles E. Schmidt College of Science

Identifier

FADT14806

Format

pdf

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