Three Causes for Disqualification of a Weight Lifting Bench:
1.Failure to observe the Chief Referee’s signals at the commencement, during or completion of the lift.
2. Any change in the elected lifting position during the lift proper i.e. any raising movement of the head, shoulders, or buttocks, from the bench, or lateral movement of hands on the bar.
3. Heaving, or sinking the bar into the chest or abdominal area after it is motionless in such a way as to make the lift easier