This is a very common problem in the culture in which we live increasingly sedentary, and that can actually be enhanced by the abuses of power training. At the lowest level, what happens is that the chest muscles are too tight and back muscles become too tight, so that the shoulders are pulled in tight chest muscles ...

... An important reason for too much sitting in a flexed position, as at this time, while you (or will) sit folded and hung on your laptop, desktop or mobile device. As you can imagine, this position allows the muscles of the chest and stretches the muscles of the back. This becomes a problem when it is made constant over longer periods. The problem, as by a disproportionate number of weight lifting exercises, push muscles (eg, chest, triceps, shoulders) and exercises the muscles that pull back (eg, biceps, rear deltoids) include exaggerated.

The solution?

* Expands the chest and other muscles (see "shoulder dislocation" link, and also see the "chest is" link) draw
* More traction exercises (see "Weights" below for an overview of strength training, the site also has a database of exercise)
* Take frequent (eg every 15-20 minutes) to sit for long periods of time and do some "stretching, if possible, otherwise just walk or stand for at least a few seconds. This may seem unnecessary, but because the repetitive parts of the Act, compliance with these suggestions will greatly reduce the negative effects of long down to the amount of time that you reduce yourself in a bad position postural
* Consult a qualified physiotherapist or a similar type of doctor.