Thumb

Forward fold : thumb side of wrist

A simple forward fold of the thumb side of the wrist.

Forward fold : thumb, first knuckle

A simple forward fold of the first knuckle of the thumb.

Backward arch : thumb

A back arch which goes almost as much sideways as backwards.

Try to keep your whole hand in the same plane.

Backward arch : wrist and thumb

A composite back arch - covering the wrist and all the thumb knuckles.