The high jump requires an athlete to jump, leaping off of one foot, over a horizontally lying bar. The crossbar is held in the air by high jump standards, which are usually metal stands that are marked with height measurements. If the crossbar (usually fiberglass), is dislodged from the standards during an athlete's jump, the jump is considered failed. If the athlete clears the crossbar with their entire body, the jump is successful.
The bar is raised each time the athletes clear a height and the athlete who clears the greatest height wins the competition. If a jumper fails three consecutive jumps, that athlete is eliminated from the competition.
Besides dislodging the bar, a jump is ruled failed if the athlete jumping touches the ground or advances beyond the plane of the near edge bar before clearing the height of the crossbar.
In the event of a tie, there is a 'jump-off', which begins at the next greater height from where the last successful jumps were made. Each athlete is given one attempt and the bar is lowered until only one athlete
These shoes have very thick soles to increase stability when leaping. This allows for a more comfortable take-off. Also, the shoes feature 'spikes' on their bottoms for traction while approaching the jump. In many cases there are holes in the heel of the shoe that the athlete jumps off to allow them to add spikes for traction in their curve if desired. This lets the athlete run faster into their turn before the jump without losing balance.
IAAF regulations state that the number of spikes in the sole cannot exceed 11. Standard configuration is six spikes in the front sole and four spikes in the heel. IAAF also regulates the maximum thickness of the shoe's sole for high jump and long jump, but not in any other track and field events.