Control of the dominant and nondominant hand : exploitation and taming of nonmuscular forces

• Published in: Experimental brain research Vol. 178; no. 3; pp. 363 - 373
• Main Author: HEUER, Herbert
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.04.2007; Springer Nature B.V
• Subjects: Action Potentials - physiology; Adolescent; Adult; Applied physiology; Biological and medical sciences; Biological Clocks - physiology; Biomechanical Phenomena; Central Nervous System - physiology; Efferent Pathways - physiology; Electromyography; Female; Fingers - innervation; Fingers - physiology; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Hand - innervation; Hand - physiology; Hominids; Human physiology applied to population studies and life conditions. Human ecophysiology; Humans; Hypotheses; Male; Medical sciences; Models, Neurological; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor Neurons - physiology; Movement - physiology; Muscle Contraction - physiology; Muscle, Skeletal - innervation; Muscle, Skeletal - physiology; Neuropsychological Tests; Reaction Time - physiology; Sex Characteristics; Transports. Aerospace. Diving. Altitude; Vertebrates: nervous system and sense organs; Force; Body movement; Oscillation; Tapping task; Muscle; Feedforward; Dynamic model; Hand; Power spectrum
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-006-0747-5

Movements of the dominant and nondominant hand have been claimed to differ with respect to how they take intersegmental dynamics into account. Consistent with this claim, movements of the dominant hand are hypothesized to better exploit the intrinsic limb dynamics, whereas movements of the nondominant hand are controlled to make the intrinsic dynamics ineffective as far as this is possible. For rapid finger oscillations this hypothesis implies a higher level of co-contractions in the nondominant than in the dominant hand. Replicating previous findings on finger tapping, finger oscillations of the dominant hand were faster and less variable than those of the nondominant hand. More importantly, the variance of the relative difference between myoelectric signals of antagonistic muscles and thus the power of reciprocal myoelectric activity was smaller in the nondominant hand, indicating a relatively higher level of co-contractions than in the dominant hand. In addition, a spectral decomposition of the total power of the relative-difference signal revealed stronger relative power in the frequency band of the finger oscillations in the dominant than in the nondominant hand. These findings are consistent with the hypothesis that for the dominant hand more accurate feedforward control is possible based on a more accurate internal model of limb dynamics.