Generalization of automatic gain scaling to coactivation

Ascertain whether automatic gain scaling of spinal stretch reflexes observed under background loading of agonist muscles generalizes to scenarios involving voluntary muscle coactivation without background loads, and quantify any differences in spinal excitability and reciprocal inhibition.

Background

Background loads are widely used to control baseline muscle activity and are known to amplify spinal reflexes via automatic gain scaling. However, background loads inherently enforce reciprocal activation patterns and alter spinal excitability.

The authors explicitly state uncertainty about whether findings from background-load paradigms generalize to voluntary coactivation conditions.