The wave (known as the Mexican wave in the English-speaking
world outside North America) is an example of metachronal rhythm
achieved in a packed stadium when successive groups of
spectators briefly stand, yell, and raise their arms.
Immediately upon stretching to full height, the spectator
returns to the usual seated position.
The result is a wave of standing spectators that travels through
the crowd, even though individual spectators never move away
from their seats. In many large arenas the crowd is seated in a
contiguous circuit all the way around the sport field, and so
the wave is able to travel continuously around the arena; in
discontiguous seating arrangements, the wave can instead reflect
back and forth through the crowd. When the gap in seating is
narrow, the wave can sometimes pass through it. Usually only one
wave crest will be present at any given time in an arena,
although simultaneous, counter-rotating waves have been
produced.