Muscle coactivation primes the nervous system for fast and task-dependent feedback control

TL;DR

This paper proposes a novel perspective that muscle coactivation primes the nervous system for rapid, task-specific responses to sensory stimuli, challenging traditional views of coactivation solely as resistance.

Contribution

It introduces a new functional role for muscle coactivation in preparing the nervous system for fast, flexible feedback control during movement.

Findings

Muscle coactivation facilitates rapid responses to sensory input.

Distributed neural control mechanisms enable task-dependent muscle activation.

Coactivation enhances the nervous system's ability to produce quick, adaptable movements.

Abstract

Humans and other animals coactivate agonist and antagonist muscles in many motor actions. Increases in muscle coactivation are thought to leverage viscoelastic properties of skeletal muscles to provide resistance against limb motion. However, coactivation also emerges in scenarios where it seems paradoxical because the goal is not to resist limb motion but instead to rapidly mobilize the limb(s) or body to launch or correct movements. Here, we present a new perspective on muscle coactivation: to prime the nervous system for fast, task-dependent responses to sensory stimuli. We review distributed neural control mechanisms that may allow the healthy nervous system to leverage muscle coactivation to produce fast and flexible responses to sensory feedback.