A good posture or optimal ergonomics are important to prevent or limit desk related back pain, neck pain and work related arm and shoulder pain. Make sure you have a good adjustable ergonomic chair. Ask your physiotherapist for advice on the correct seat height, desk height, arm support and ergonomic chair and desk recommendations.
Tips on the optimal sitting posture at your desk:
Sit with your feet flat on the floor. Your feet should be parallel to each other and hip width apart.
Use the correct seat height. Your hips need to be higher than or level with your knees, but not lower.
Use the whole seat. Move your buttocks all the way to the back of the seat. Do not sit on the edge of your chair. This habit causes your back muscles to overwork.
Use the whole back rest. Sit upright from your lower back and don’t over correct by arching the high part of your lower back.
Use the correct working height. Your forearms should be supported on the desk. If you need to slump to get your forearms on the desk, the desk is too low relative to your seat. If your shoulders are pushed up when your forearms are on the desk, the desk is too high relative to your seat.
Do not sit too far from your desk. You should sit as close as possible to the working surface. Your abdomen should nearly touch the desk.
Keep your mouse and keyboard close to you so that your arms do not need to stretch out towards them. That would cause tension in the neck and shoulder muscles and contribute to irritating the nerves.
Computer screen needs to be directly in front of you at eye level. If your screen is even slightly off to one side your neck muscles will become unbalanced.
If using a laptop lift the back of the laptop by using a laptop stand or even a book.
Clear the area under your desk of clutter so you can easily wheel to the left and right if you need to work on something else and keep your work directly in front of you.