The "8" handshape is often used to represent the process of
"kicking." It is also sometimes used to show explosive
propulsion (such as something being blasted out of a cannon).
Examples:
The kicking of a football
The firing of a cannon
The detonation of a projectile
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American Sign Language (ASL) online at American Sign Language University ™
ASL resources by Lifeprint.com © Dr. William Vicars