Pathological Upper Limb Synergies of Patients with Poststroke Hemiparesis

This review presents current data on possible mechanisms forming synergies in health, particularly at the cortical level. The mechanisms of formation of pathological synergies, taking account of the anatomical and physiological characteristics of the upper limbs and the hypothesis, that synergistic patterns are transformed in patients with spastic hemiparesis are discussed. Current views of the pathophysiological bases of the formation of pathological synergies based on neuroimaging and neurophysiological study data are presented, along with a method for noninvasive stimulation of the brain. The question of the correction and transformation of pathological synergies in rehabilitation practice is discussed. Particular attention is paid to clinical and instrumented evaluation of synergies and the use of validated clinical scales and instrumented methods such as video movement analysis, electromyography, magnetic and contactless tracking systems, and virtual reality technologies.