Javelin - General Rules.

Javelin - General Rules.
One. None javelin shall be valid without the metal tip of the head of the dart has wounded the ground before any other
part of the dart or if the competitor touches with any part of his body or limbs, or the arc lines
marked perpendicular parallel lines or the ground beyond these lines.

2nd. In no time, having prepared for the javelin throw and the javelin until it has been released into the air, the bidder may
rotate through so that your back is facing the sector launch.
3rd. Only material from release provided by the organizer can be used. No competitor may bring
any implement into the field.

4th. The dart must be thrown over the shoulder or upper arm launcher and should not be released as sling.
Note: There are allowed unorthodox styles.
5th. All entries to be valid, should fall into the inside of the lines marking the sector in
ground and that extends from the center of the arc of the circle of which the arc is a part, extend for a length of 100m
limiting the parallel runway. The ends of the sector shall be marked with flags in the sector, which measures
approximately 29 °.

6th. If the dart break when in the air, the attempt will not be counted, since the javelin throw has been made of  according to the rules.

Source: Athletics