Explore "Alpine Notes and the Climbing Foot" by George Wherry on Textopian. Read with annotations and highlights.
It has often been noticed in mountaineering that a guide can go face forward and whole-footed up a slope, while the amateur following, and coming to the steep part, cannot plant his whole foot upon the slope, but has to go on his toes or else turn sideways.
The difficulty with the young climber seems to be to get his heel down, and he learns to look out for little humps or embedded stones on which he may place his heel.