Put somebody off their stride
Definition 1 of 1
Pro Tip 1/3Use in Context
Apply the phrase in situations where a temporary distraction has caused a problem in concentrating or continuing. 
The construction noise outside put me off my stride while I was studying.
Pro Tip 2/3Emotional Impact
The phrase may suggest frustration or annoyance because of the disruption. 
A heckler in the crowd put the comedian off his stride, visibly irritating him.
Pro Tip 3/3Not Literal
Understand that the phrase is usually metaphorical, not referring to actual walking or running. 
Her sudden resignation really put the team off their stride with the project.