Functional networks of muscle fibers facilitate inter-muscular coordination

Abstract

Fundamental movement patterns require continuous skeletal muscle coordination, where muscle fibers with different timing of activation synchronize their dynamics across muscles with distinct functions. It is unknown how muscle fibers integrate as a network to generate and fine tune movements. Here we investigate how distinct muscle fiber types dynamically synchronize as a network across muscles and respond to fatigue during consecutive bouts of maximal exercise. We uncover that a complex inter-muscular network of muscle fiber cross-frequency interactions underlies basic movements. The network exhibits hierarchical organization of sub-networks and modules with specific links strength stratification profile, reflecting distinct functions of the muscles involved in movements. We find complex network reorganization with fatigue where network modules follow distinct phase-space trajectories reflecting their functional role and adaptation to fatigue. The findings reveal general principles of inter-muscular coordination for fundamental movements, and open a new area of research, Network Physiology of Exercise.

Resilience in sports through the lens of dynamic network structures

“…Note that if a stressor is resisted and no perturbation occurs, the functional reorganization of the network may not occur(Den Hartigh & Hill, 2022).2 The same functional output may also be achieved from different network configurations (i.e., degeneracy,Edelman & Gally, 2001). Therefore, a precise definition of the level of functioning to which the system returns is warranted.3 Inspirations for additional sophisticated approaches for network-based analyses can also be inferred from recent publications in the domain of network physiology (e.g.,Bashan et al, 2012;Bartsch et al, 2015;Rizzo et al, 2020;Rizzo et al, 2022;Garcia-Retortillo et al, 2023).Frontiers in Network Physiology frontiersin.org…”