The three-barred Cross, as shown above is the most common shape used in the Orthodox Church – whether as simple adornments, crucifixes, or in Icons which show the Cross, the three bars are usually present.
The short, extra top bar represents the sign nailed to Christ’s Cross, which read: THIS IS THE KING OF THE JEWS (Luke 23:28; in John’s Gospel the sign reads: “Jesus of Nazareth, King of the Jews”)
The lower, slanted, bar is the foot-rest of the crucifix. All crucifixes would have had these, as no one could be suspended from a cross by nails alone. The cruel death of a crucifixion was not brought about through blood loss, but by lack of oxygen: exhausted, the man is no longer able to stand straight upon the foot-rest, the body sags, and air can no longer be drawn in.
The foot-rest of Christ’s Cross is slanted because it is believed that in the final moments before Jesus gave up His spirit, His flesh spasmed and the foot-rest was kicked out of place. But in this true event there is also symbolism. The foot-rest points up, toward Heaven, on Christ’s right hand-side, and downward, to Hades, on Christ’s left. One of the Orthodox Church’s Friday prayers clearly explains the meaning:
In the midst, between two thieves, was Your Cross found as the balance-beam of righteousness;
For while one was led down to hell by the burden of his blaspheming,
The other was lightened of his sins unto the knowledge of things divine.
O Christ God glory to You
(c.a. Luke 23:39-43)