title: The pattern of coupling dynamics between postural motion, isotonic hand movements and physiological tremor.
abstract: This study was designed to examine differences in the coupling dynamics between upper limb motion, physiological tremor and whole body postural sway in young healthy adults. Acceleration of the hand and fingers, forearm EMG activity and postural sway data were recorded. Estimation of the degree of bilateral and limb motion-postural sway coupling was determined by cross correlation, coherence and Cross-ApEn analyses. The results revealed that, under postural tremor conditions, there was no significant coupling between limbs, muscles or sway across all metrics of coupling. In contrast, performing a rapid alternating flexion/extension movement about the wrist joint (with one or both limbs) resulted in stronger coupling between limb motion and postural sway. These results support the view that, for physiological tremor responses, the control of postural sway is maintained independent to tremor in the upper limb. However, increasing the level of movement about a distal segment of one arm (or both) leads to increased coupling throughout the body. The basis for this increased coupling would appear to be related to the enhanced neural drive to task-specific muscles within the upper limb.
authors: School of Physical Therapy and Athletic Training, Old Dominion University, United States. Electronic address: smorriso@odu.edu.
authors: S
authors: S
authors: Morrison
authors: School of Recreation, Health, and Tourism, George Mason University, United States.
authors: N
authors: N
authors: Cortes
authors: Department of Kinesiology, Pennsylvania State University, United States.
authors: K M
authors: KM
authors: Newell
authors: School of Exercise and Nutrition Sciences, Queensland University of Technology, Australia.
authors: G
authors: G
authors: Kerr
mesh_terms: D000054:Acceleration; D004576:Electromyography; D005385:Fingers / Q000502:physiology; D005542:Forearm / Q000502:physiology; D006225:Hand / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement; D018482:Muscle, Skeletal / Q000502:physiology; D004856:Postural Balance; D011187:Posture; D014202:Tremor; D055815:Young Adult
keywords: Acceleration; Bilateral coupling; Physiological tremor; Postural sway