Poor posture can often lead to back pain. Here is a simple exercise you can do at your desk that can strengthen your core and lower back and, in turn, that will lead to a more upright outlook on life.
Sit up at the edge of your chair with both feet flat on the ground shoulder-width apart. Imagine a string running from the ceiling to the top of your head pulling it upwards. As it pulls, each vertebrae separates and the natural curves of the spine become accentuated.
Now tuck your chin in as if trying to touch it to the back of your head through your skull. This should provide a deep stretch to the muscles that connect the spine to the base of the skull.
Take a deep breath in, filling the belly, and rotate your hands outwards bringing the shoulder blades together as if squeezing a pencil between them. Hold this position for 15 to 20 seconds and slowly breathe out and relax
Repeat this exercise whenever it feels like poor posture is creeping in again. This will help change the muscle memory of poor posture to good posture.