Figure 8d. Hand posture. (a) Absence of elbow rests causes the elbows to hang downward. (b) Sitting too close to the keyboard causes the arms to be raised to the sides. (c) Sitting too far from the keyboard causes the arms to be overextended. (d) Keeping the monitor and keyboard at an angle creates a bad angle for the wrists. (e) Keeping the mouse far from the keyboard causes undue stretch during use. (f) With optimal posture, the upper arms are relaxed at the sides with the elbows as close to the body as possible. The forearms should be horizontal and at right angles to the upper arms (black lines).