While sitting at a computer desk, a person's hands, wrists, forearms and thighs should be straight and nearly parallel to the floor, while the back should be supported with appropriate lumbar support. In addition, the elbows should be bent at 90 degrees and stay tucked in close to the body.
Using improper posture when working at a computer can increase the risk for developing musculoskeletal disorders. When proper posture is used consistently, this risk is reduced, as is the risk of intermediate strain on the muscles and skeletal system.
Sitting in the same position for an extended period of time is still unhealthy, even if proper posture is being used. It is important to take small walks or stretch frequently throughout the day.