Force control improvements in chronic stroke: bimanual coordination and motor synergy evidence after coupled bimanual movement training

• Published in: Experimental brain research Vol. 232; no. 2; pp. 503 - 513
• Main Authors: Kang, Nyeonju, Cauraugh, James H.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2014; Springer; Springer Nature B.V
• Subjects: Aged; Aged, 80 and over; Analysis; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Electric Stimulation; Electromyography; Entropy; Exercise Movement Techniques - methods; Female; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Hand Strength - physiology; Human mechanics; Humans; Isometric Contraction - physiology; Male; Medical sciences; Middle Aged; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Movement - physiology; Muscle, Skeletal - innervation; Neurology; Neurosciences; Psychomotor Performance - physiology; Range of Motion, Articular - physiology; Reaction Time; Rehabilitation; Research Article; Stroke; Stroke (Disease); Stroke Rehabilitation; Time Factors; Vascular diseases and vascular malformations of the nervous system; Vertebrates: nervous system and sense organs; Stroke; Bimanual motor synergy; Force control; Bimanual coordination; Motor recovery; Coupled bimanual movement training; Nervous system diseases; Cardiovascular disease; Motor control; Cerebral disorder; Vascular disease; Chronic; Bimanual task; Central nervous system disease; Cerebrovascular disease
• ISSN: 0014-4819; 1432-1106; 1432-1106
• DOI: 10.1007/s00221-013-3758-z

Bimanual movement disorders are common dysfunctions post stroke. This stroke study investigated bimanual force control capabilities to determine the effect of coupled bimanual movement training on bimanual coordination and motor synergy. Stroke participants ( N  = 11) completed three bimanual force control tasks at 5, 25, and 50 % of maximum voluntary contraction before and after coupled bimanual movement training. Root mean square error (RMSE), approximate entropy, correlation, and bimanual motor synergy were analyzed in two-way completely within-subjects ANOVAs (Test Session × Force Level: 2 × 3). Multiple linear regression analysis determined the relationship between RMSE and other force control measures. The analyses revealed three important findings: (1) RMSE decreased from baseline to posttest (2) negative correlation (e.g., error compensation) and bimanual motor synergy increased at 25 and 50 % after rehabilitation, and (3) increased bimanual motor synergy was strongly associated with decreased RMSE after training. The findings indicate that coupled bimanual movement training improved force control performance, bimanual coordination, and motor synergies. Indeed, the present findings extend bimanual motor synergies as a meaningful indicator for estimating task performance improvements. Finally, bimanual force control is a valid outcome measure in quantifying progress toward motor recovery post stroke.