With repetition, the connective tissue layers begin to get stiff and to stick to one another, like ironing two thin sheets of plastic together. As a result, the body becomes stuck in that position and, even when the briefcase is not being carried, the shoulder still remains lower. The whole body will adjust to this imbalance, and soon the impact of the briefcase will be reflected throughout the entire body. An example of one's emotional attitude causing imbalance in the body can be seen when we are depressed, which is often characterized by a sunken chest. If this feeling and the bodily stance become a continual patterns, the body becomes glued in this posture.
Imbalance is also cause through physical trauma.
For example, if you were to injure your leg, you would be likely to walk in an imbalanced and even awkward way to protect injury. After a time, that movement pattern might become a part of your body's way of moving, even thought the injury had been healed long ago. As described in the discussion of connective tissue, this tension is then reflected through the body and further influences our movement patters. As life goes on and again continues, more and more of these patterns become embedded in our connective tissue simply because we don't move freely. In our misalignment, gravity becomes the enemy, compounding and magnifying any stress that is there.