Functional integration of coactivation mechanisms

Ascertain whether the neurophysiological mechanisms by which muscle coactivation primes feedback—dual engagement of agonist and antagonist via feedback loops, motor unit recruitment properties, spindle sensitivity modulation, and neuromodulatory arousal—act in parallel or independently, and determine how their relative contributions depend on the task goal and features of the limb and environment.

Background

The authors propose several candidate mechanisms that could explain how coactivation primes fast, flexible feedback responses. These include distributing control across muscle pairs, exploiting recruitment properties, tuning spindle sensitivity, and engaging arousal circuits.

However, they explicitly state uncertainty about whether these mechanisms operate in parallel or independently and how their contributions are modulated by task or environmental context.