As a massage therapist I think I worked most on low back problems and on shoulder and neck problems. Now-a-days we spent so much time behind our computer with our neck bend forward that our shoulders and neck muscles suffer to an extend that our body can’t ‘repair’ it anymore by itself. Massage is a good option. Yoga as well. If you do the correct poses, like the ones in this free yoga class to open up shoulders.
There is a big difference by doing exercises and doing the right exercises. A lot of people spent hours and hours in a sport school or yoga shala. Perfect. As long as you or your trainer / teacher know what you are doing. Especially men like to work out hard in the gym: lifting weights, doing pull-ups and so on. The problem is: if your neck muscles and shoulder muscles are already stressed you will only stress them more by making them work hard. The trick is to find the correct balance by working your muscles and relaxing them and by strengthening your muscles and lengthening them.
What you do behind your computer is lengthening the muscles of your back and neck, but at the same time making them weaker as well. What also is happening, because of your posture, is that you are shortening your chest muscles. Doing a lot of weight lifting or a lot of chaturanga dandasanas, planks, pincha mayurasanas and handstands in your yoga class will only make the situation worse. Stretching your pectorals muscles (chest) and shoulder muscles will keep your muscles on the front and back in balance. This sequence is definitely going to open up your shoulders.
Have fun with it and go slow.