To and fro
Definition 1 of 1
Pro Tip 1/3Physical Movement
Used to describe literal physical motion, not mental or emotional states. 
The cat's tail moved to and fro as it watched the bird.
Pro Tip 2/3Slight Repetition
Implies a repetitive, often small-scale movement, not traveling long distances. 
She rocked the baby to and fro in her arms to soothe him.
Pro Tip 3/3Indecision
Can metaphorically suggest indecision or vacillation in one’s actions or thoughts. 
His opinions swung to and fro depending on the crowd.