Why do I often feel back pain when I have to sit for a long time at work?

Poor posture at work is a common cause of back pain. Prolonged use of the computer and writing in a desk-bound position can lead to a constant state of tension in the back muscles and spine, which can cause chronic cumulative damage over time. Taking care to sit in a reasonable position and standing up intermittently to give the muscles of the lower back the rest they need (a combination of work and rest) may prevent back pain from occurring.