![]() Recent studies have demonstrated synergies at the level of hypothetical control variables associated with spatial referent coordinates for effectors. The ability of the central nervous system to attenuate synergies in preparation for a quick action-anticipatory synergy adjustments-is emphasized. Two aspects of synergies are described: organizing elements into stable groups (modes) and ensuring dynamical stability of salient performance variables. We revisit the concept of synergy based on the recently translated classical book by Nikolai Bernstein (On the construction of movements, Medgiz, Moscow 1947 Latash, Bernstein’s Construction of Movements, Routledge, Abingdon 2020b) and progress in understanding the physics and neurophysiology of biological action. ![]() These findings can help in the walking-training concept to improve muscle synergy deficits in stroke survivors. The RAC condition demonstrated a more complex representation of muscle synergy than the CWS condition the change in single-leg support time on the paretic side related to the changes in muscle synergy more than changes in lower-limb angle. Hierarchical multiple regression analysis revealed that the change in VAF1 was explained by change in single-leg support time (R² = 0.43, p = 0.002). VAF1 was decreased in the RAC condition (73.9 ± 0.15) compared to that in the CWS condition (76.9 ± 0.13, p = 0.002). In the RAC condition, lower-limb flexion and knee flexion angles, single-leg support time on the paretic side, and the symmetry index of single-leg support time were increased compared to those in the CWS condition. Factors related to the complexity of muscle synergy (variance accounted for VAF1) between the walking conditions were examined using hierarchical multiple regression analysis. Single-leg support time, kinematics, and electromyograms were measured. The participants were assessed in a random block design under two conditions: comfortable walking speed (CWS) and walking with RAC. Wards at two medical corporation hospitals.įorty stroke survivors (mean age, 70.4 ± 10.3 years time since stroke, 72.2 ± 32.3 days) who could walk without physical assistance. To examine the relationship between temporal asymmetry and complexity of muscle synergy during walking using rhythmic auditory cueing (RAC) and the factors related to changes in muscle synergy during walking with RAC in stroke survivors. Meanwhile, many of these physiologic features have found their way in the control of very flexible walking bipedal robots. This activation is controlled by afferent input (facilitation by a broad range of afferents, suppression by load afferent input). The latter structure forms the core of a new asymmetric model of the CPG. More specifically, it is suggested that the responses in that period relate to the activation of a flexor burst generator. It is proposed that this is linked to the activation of circuitry that is responsible for the generation of locomotor patterns (CPG, "central pattern generator"). In particular, the end of the stance phase is a period when the flexor synergy is facilitated. In addition, it will be shown that there is a great flexibility in the expression of some of these modules during gait, thereby allowing for a phase-dependent modulation of the appropriate responses. It will be argued that there is large overlap between these notions on modules and the older concepts of reflexes. Similarly, the relation between the flexor reflex and the withdrawal reflex modules of Schouenborg and Weng (1994) will be discussed. In this paper, we question how these finding build upon the original work by Sherrington, who proposed that the flexor reflex is the basic building block of flexion during swing phase. One of the basic modules involves the flexion of the leg during swing and it was shown that this module is already present in neonates (Dominici et al., 2011). Recently there has been a growing interest in the modular organization of leg movements, in particular those related to locomotion.
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