A bondage position, where the submissive is bound into a position resembling a ball.
Referring to the bondage position, where a person is tied up into a ball or fetal position, using various restraints, mostly ropes. It is referred to as being ball tied, due to its resemblance to being a ball, or in some instances, referred to as being hog tied. (Purists would disagree to that usage)
This is done where a person is tightly tied into a shape, resembling a ball. Usually the legs are bound, with the heel tied pressing inwards an up.
The legs are generally bound as are the ankles to further restrict any movement. The legs are placed upwards, though folded, with the feet being forced inwards.
The head and torso is then bent over the legs, or the legs brought upwards, to complete the circle. Hands and arms are generally positioned behind the back, and tied to the body.
However, they can be tied in front, with them hugging the legs.
Essentially, the submissive is forced to be in a fetal like position.
Noteworthy: One of the forms of self bondage, though due to its restrictive nature, care should be shown, to insure a means of escape. Proper safety procedures should always be taken, when indulging in self bondage.