Merging of synergistic muscles and intermuscular coherence predict muscle coordination complexity

Alterations in Muscle Networks in the Upper Extremity of Chronic Stroke Survivors

“…The reduced functional connectivity revealed in the study for the synergistic muscle pairs in stroke participants may explain the poor motor control in target-reaching tasks in stroke, and could be further explained by the loss or reduction of the common neural input to the muscles, likely as a result of the damage to the cortico-spinal pathways. Fisher et al also found that IMC of the first dorsal interosseous, extensor digitorum communis, and flexor digitorum superficialis muscles in the beta band (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) was associated with the integrity of the cortico-spinal tract [19].…”

“…The alteration in the proximal muscle synergies implies a potential lack of ability for post-stroke survivors to selectively activate deltoid muscles under isometric conditions. However, while muscle synergies can represent the anatomical intermuscular coordination patterns in neuromuscular control, they cannot quantify the functional connectivity among muscles such as coherence can [22].…”

Estimation of Time-Varying Coherence Amongst Synergistic Muscles During Wrist Movements

“…Therefore, the extensor muscles have same phenomenon in both MC and WE stages. Several researches have reported that intermuscular coherence exists in synergistic muscle pairs (De et al, 2015 ; Li et al, 2016 ). The interpretation maybe that the synergy mainly related to force production and the intermuscular synchronization occurs when functional forces are produced.…”

“…Considering that the NMF method can break the data into a target matrix without any negative, large studies have applied this method to analyze the muscle activation during pedaling (De et al, 2015 ), walking (Haghpanah et al, 2017 ), and elbow movement (Tang et al, 2017 ) and so on. Although muscle synergy can reflect the relationship of the combination and coordination among the multiple muscles and provide insight into the overall muscular activity (d'Avella et al, 2013 ), it has limitation in exploring the synchronous oscillations among muscles that play an important role in motor-control system (Li et al, 2016 ).…”

“…Farmer proposed the motor binding hypothesis that synergistic muscles were coupled by synchronous neural oscillation (Farmer, 1998 ). A few researches provide a novel perspective by combining the muscle synergy and intermuscular coherence to analyze EMG signals (De et al, 2015 ; Li et al, 2016 ). They analyzed the intermuscular coherence between each muscle pair with or without synergy based on the NMF and coherence methods.…”