Elbows bend too much — losing the wide arc
Narrow elbow angle eliminates the maximal pec stretch.
Overactive muscles
Biceps brachiiAnterior deltoid
Corrective work
Foam RollPectorals↗StretchDoorway pec stretch↗Narrow elbow angle eliminates the maximal pec stretch.
The stretch stimulus is the whole point; a fast return eliminates it.