(one's) knees knock together(redirected from his knees knocked together)
(one's) knees knock together
One is trembling or shaking uncontrollably, as from cold, fear, or anxiety. The poor kid's knees knocked together as he stood up there on stage in front of the entire school. I may seem confident when I'm leading a training seminar, but my knees still knock together most of the time. We stood outside the mall, our knees knocking together from the frigid cold as we waited for the bus to arrive.