After you have connected an Actor to a character, you may notice the animation directed onto your character results in some awkward movement. For example, the shoulders in the character may appear too low and close to the body in certain frames, or the neck may have some unnatural movements. This can occur when certain markers are poorly captured, or when the Actor configuration does not provide good capture data.
You can use the Motion Reduction settings in the Character Settings pane to adjust and fine-tune the way the chest, shoulders, neck, and head in the character react to the Actor source.
To adjust a character connected to an Actor:
This hides the Actor in the Viewer window so you can see your character clearly. Even though the Actor is hidden, it still drives the motion of the character.
For example, if the shoulders appear too low and tight to the body, set the Shoulder Reduction slider to 80 to achieve a more natural result.