Effect of synchronization of firings of different motor unit types on the force variability in a model of the rat medial gastrocnemius muscle.

ABSTRACT: The synchronized firings of active motor units (MUs) increase the oscillations of muscle force, observed as physiological tremor. This study aimed to investigate the effects of synchronizing the firings within three types of MUs (slow-S, fast resistant to fatigue-FR, and fast fatigable-FF) on the muscle force production using a mathematical model of the rat medial gastrocnemius muscle. The model was designed based on the actual proportion and physiological properties of MUs and motoneurons innervating the muscle. The isometric muscle and MU forces were simulated by a model predicting non-synchronized firing of a pool of 57 MUs (including 8 S, 23 FR, and 26 FF) to ascertain a maximum excitatory signal when all MUs were recruited into the contraction. The mean firing frequency of each MU dep

SUBMITTER: Raikova R 

PROVIDER: S-EPMC8101995 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature