When the terrain takes the lead

This applies to running as well as skiing. I mean running on snow or uneven terrain, when the foot lands in such way that it forces a response to adapt to a situation that is neither desired not necessarily safe. It probably applies to many other sports that involve running and intimate foot-to-ground contact.

The same, to an even larger extent, is true of alpine skiing. The ever changing terrain dictates some response from the skier and that signal changes all the time. With today's extensive grooming, there is not much need for that precise response, but as soon as a skier leaves the “corduroy” to ski the rest of the mountain, the feet need to return to a state of nimbleness and must be just like the most effective car suspension ever devised.

This is a learned skill through miles and hours of practice and it often stands as the difference between the casual and the real, skilled athlete.