Upper crossed syndrome (also sometimes called shoulder girdle crossed syndrome) is a very common postural pattern first described by Dr. Vladimir Janda. It describes changes in the position of the head, neck, and shoulders in relation to one another. The postural changes occur when particular groups of agonist and antagonist muscles are out of balance with one another. Some muscles have become short and tight, while others are over-stretched and weak. As in lower crossed syndrome, the muscles that are out of balance with one another in upper crossed syndrome form a cross when viewed from the side of the body. That cross is centered around the shoulder girdle.