The most common incorrect posture that individuals assume when seated are hunching and slouching. The former causes the overcurving of the upper back due to weakening of the muscles in the said area. Meanwhile, the latter causes the tightening of several muscles in the body and especially harms the lower back.
Apart from these, forward head can be caused by spending long hours in front of a computer and can lead to what is called the tech neck syndrome, a condition that causes pain on the neck, shoulders, upper back, and the head.