RT Journal Article
SR Electronic
T1 Active hydraulics and odd elasticity of muscle fibers
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.02.20.481216
DO 10.1101/2022.02.20.481216
A1 Shankar, Suraj
A1 Mahadevan, L.
YR 2024
UL http://biorxiv.org/content/early/2024/02/28/2022.02.20.481216.abstract
AB Muscle is a complex hierarchically organized soft contractile engine. To understand the limits on the rate of contraction and muscle energetics, we construct a coarse-grained multiscale model that integrates over molecular details and describes muscle as an active sponge. Our analysis of existing experiments highlights the importance of spatially heterogeneous strains and local volumetric deformations in muscular contractions across species and muscle type. The minimal theoretical model shows how contractions generically induce intracellular fluid flow and power active hydraulic oscillations, which determine the limits of ultrafast muscular contractions. We further demonstrate that the viscoelastic response of muscle is naturally nonreciprocal – or odd – owing to its active and anisotropic nature. This points to an alternate mode of muscular power generation from periodic cycles in spatial strain alone, contrasting with previous descriptions based on temporal cycles. Our work suggests the need for a revised view of muscle dynamics that emphasizes the multiscale spatio-temporal origins of soft hydraulic power, with potential implications for physiology, biomechanics and locomotion.Competing Interest StatementThe authors have declared no competing interest.