Colleen.JPG [6/29] Description: Colleen on rapelle - Prusik knot in-hand. The Prusik knot is the best known of a family of knots that are used to attach a moving "clamp" to another rope. A Prusik (or Prussik or Prussic) is a friction hitch named for its inventor, Austrian mountaineer Dr. Karl Prusik. (photo by Paul)