This is a
skateboarding and
snowboarding trick which is similar to a
tweak. It is usually used with
grabs which cannot employ the
tweak, though most
grabs can use a bone.
There are only two types of bones. They are the nosebone and the tailbone. As they would suggest they use either the nose or tail.
To do a bone you must simply extend your leg completely. If you are doing a nosebone then you extend your front leg, if you are doing a tailbone then you extend your back leg. The most common useage of this is the Indy Nosebone. Other uses include: Nose Tailbone, Tail Nosebone, Japan Nosebone etc.