Most of us that are confined to an office for over 8 hours a day have developed a problem with poor posture. It is almost inevitable that we will sit at our desk in a way that can hurt our bodies later.
We have all heard that sitting for that long every day of your working life can take years off of your life. While that is debatable, what is for certain is that when you have poor posture while sitting at your desk, you will develop a sore neck, back, or shoulders. Sitting with your shoulders shrugged and head forward puts a lot of unnecessary pressure on your neck and you will start to feel the effects of that over time.
One possible solution is to get a standing desk for your office. There are several options here with many different price ranges. In the mid range of prices is a desk from Ikea that sells for around $600. It is totally automatic with an electric motor so you can stand for most of the time but when you start getting tired you can quickly lower the desk. It only takes about 10 seconds to go from sitting to standing and vice versa. There are other cheaper options with one costing just $25. That one is being offered by the people that run Hootsuite and is made of totally collapsible cardboard so you can easily carry it with you and set it up in seconds. If you are totally broke you can just set up some boxes on top of your normal desk to see if you really can stand for hours at a time.
The bottom line is that we all have to get up and move around a lot more than we do now. People were not made to sit a desk for hours at a time without moving. Besides the problems with pain caused by a sedentary lifestyle, we also have to worry about being overweight because we just don't get enough exercise.
Here is a very short video that shows how most of us used to watch TV when we were young - we need to do more of that when we are adults.