Interactions among mechanisms linking coactivation to enhanced feedback control

Determine whether proposed mechanisms through which muscle coactivation primes feedback control—including dual engagement of agonist and antagonist muscles, motor unit recruitment changes, modulation of muscle spindle sensitivity via α–γ or β motoneurons, and neuromodulatory arousal inputs—operate in parallel or independently, and quantify how their relative contributions depend on task goals and limb or environmental properties.

Background

The authors propose multiple neurophysiological mechanisms that could link coactivation to faster and more flexible feedback control, ranging from spinal motor pool properties and motor unit recruitment to spindle sensitivity and neuromodulatory arousal systems.

They emphasize that it is unknown whether these mechanisms are engaged concurrently or separately and how each mechanism's contribution varies with specific task demands or environmental conditions.