put one off stride

put one off one's stride

 
1. Lit. to cause one to deviate from a rhythmic stride while walking, running, or marching. A rabbit ran across the path and put me off my stride.
2. Fig. to interfere with one's normal and natural progress or rate of progress. Your startling comments put Larry off his stride for a moment. He was put off his stride by an interruption from the audience.
See also: off, one, put, stride