Your keyboard or mouse is too far away.
Reaching for these items can cause you to lean forward or slump over. Make sure that you can easily reach your keyboard or mouse when sitting in an upright or slightly reclined position. You may also want to consider a keyboard tray with enough room for your mouse. See Keyboard Setup and Usage or Mouse Setup and Usage.
Your backrest's too low, or tilted incorrectly.
Inadequate back support can force you to overuse your back muscles, leading to fatigue or discomfort. See Chair Setup and Usage.
You're not maintaining proper posture.
Proper posture is essential, and helps minimize the strain on your muscles and joints. See Chair Setup and Usage.
Your phone, or calculator is too far away.
Just like an incorrectly positioned keyboard or mouse, reaching for these items can cause you to lean forward or slump over. Make sure that you can easily reach your these items when sitting in an upright or slightly reclined position. See Mouse Setup and Usage.
You're constantly switching CDs or disks in the CPU.
Constantly reaching to swap disks or CDs in a CPU that's not within easy reach can cause neck, shoulder, and upper back pain. Consider placing the CPU in an under-desk hanger to minimize the distance you need to reach. See Desk Overview and Accessories.
Your chair isn't adjusted properly.
If your chair has an adjustable backrest, tilt, seat pan, or lumbar support, make sure they're adjusted to correctly fit you. See Chair Setup and Usage.