THE PERSISTENCE OF INTERLIMB COORDINATION DURING BIMANUAL MOVEMENTS

Open Access
Author:
Kane, Siobhan Louise
Area of Honors:
Kinesiology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Dr Robert Sainbug, Thesis Supervisor
  • Robert L Sainburg, Thesis Supervisor
  • Andrzej Przybyla, Thesis Supervisor
  • Stephen Jacob Piazza, Honors Advisor
Keywords:
  • bimanual coordination
  • kinesiology
  • neural movement control
Abstract:
Previous literature has shown that there are substantial interlimb differences in coordination during unimanual movements. The dominant arm is typically more efficient in controlling intersegmental dynamics and the nondominant arm has an advantage for maintaining limb posture. Some have suggested that bimanual movements may involve different control strategies than those that are used during unimanual movements. Additionally, research has shown that interlimb differences are less when bimanually congruent joint displacement movements are completed compared to those completed that require congruent hand displacement. The purpose of this experiment was to observe if motor lateralization was affected during bilateral tasks. This was examined by comparing the coordination during unimanual and bimanual reaching movements. In this study, two hypotheses were proposed: 1) the effect of handedness would be reduced when moving bimanually compared to the movements made unimanually and 2) that bimanual movements that required congruent joint displacement would reflect less interlimb differences than those movements made with congruent hand displacement. Subjects were asked to make rapid and concise unimanual and bimanual movements to various targets, each of which had different inertial requirements. Bimanual movements consisted of those which require either congruent joint displacement or congruent hand displacement. Our results showed that interlimb differences in coordination were not changed under bimanual conditions. While we found some differences in coordination between joint congruent and hand congruent conditions, further comparison (outside of this current analysis) suggest that these differences persist during matched unimanual comparison, and therefore cannot be attributed to bimanual movement conditions. Based on our analysis, we suggest that the mechanisms which synchronize bimanual movements may occur upstream in the control process to the expression of motor lateralization and consequently, might not affect the expression of interlimb differences in coordination. This, in turn, indicates that bimanual coordination does not alter the mechanisms that determine intralimb coordination patterns. Additionally, our results challenged the conclusion of a difference in congruent joint displacement and congruent hand displacement movements; rather, the movements were similar in the amount of interlimb differences.