The muscles in your back and neck fight gravity and become irritated, the muscles of your front side become tight and locked down.
How can we manage this?
Posture is deep rooted in the subconscious and it is a constant battle to correct. Think of your neural pathways like a wheat field. The path most traveled - your usual posture - is flattened and the obvious default navigation choice. To create a new path you have to push your way through the tall grass again and again. It will take hundreds and hundreds (maybe thousands) of mindful treks through this new path before it gets flattened out, and for the old path to grow over.
Even if you're not interested or committed to improving your body's posture, consider the idea of micro-breaks when at work/the desk.
Micro-breaks.
These breaks should be taken before you are feeling stiff, sore, or ache-y. Ideally you should take a 20-30 second micro-break every 20-30 minutes. If you have an analog clock in view, try to associate each 20 minute mark with standing up and getting your body moving, if just for a short while. Roll your neck around slowly, stretch, walk to the water cooler or bathroom, jog in place for 10 seconds - whatever is reasonable. It's entirely likely your job does not allow this type of consistent frequency, but just do what you can.
Longer breaks of 1-5 minutes should also be taken every 2-3 hours or as you need them. Try setting phone or computer reminders.
One of the most effective micro-break exercises, as well as my personal favorite, is the Brugger Relief Position. Developed by a European neurologist, this can be done in as little as 10 seconds. If you can't find a 10-second break at work, I don't know what to tell you.
Studies show it will help to reduce tension, improve breathing and improve posture within just a few weeks of practice.
Brugger's Relief Position, sitting:
1. Sit or perch at the edge of your chair. Sit on your "sit bones" just around where the top of your legs meet your butt cheeks. You don't have to feel like you're falling off the chair, though.
2. Hold your head up high. Imagine a string fixed at the crown of your head pulling you toward the sky.
3. Spread your legs slightly apart to the sides, knees above your ankles. Turn your legs outward to a comfortable degree.
4. Rest your weight on your legs and feet and relax your abdominal muscles.
5. Tilt your pelvis forward and raise your breastbone up. Another way to think of this is to bring your shoulder blades together in the back without raising your shoulders up; an arch of the back to combat the rounded forward posture present with long periods of sitting.
6. Turn your arms palm-forward, with your arms rotated outward.
7. Breathe deeply into your abdomen.
Hold this for 5-20 seconds, then relax. Feel free to repeat after ~30 seconds of rest. As always, discontinue at any point if pain is present. If anything doesn't feel right, trust that. Adjustments can always be made.
Brugger's Relief Position, standing:
1. Stand tall, with your head held high.
2. Spread legs to about shoulder width apart.
3. Turn feet outward to a comfortable degree.
4. Draw your belly in toward the spine.
5. Tilt your pelvis forward, and raise your breastbone up.
6. Turn arms out, palms up, arms slightly raised out to the side.
7. Breathe deeply into your abdomen.
Hold for 5-20 seconds, relax. Again, feel free to repeat after a short ~30 second break. Make adjustments as necessary, etc. You get the idea.
With that, I'm off to go walk around a little and stretch! I hope this finds you well, desk jockeys of the world!