Relocate your keyboard and mouse so you can reach them with your upper arms relaxed by your side. Sit closer to your keyboard and mouse. This may require you to adjust your armrests, work surface height, and other equipment. Make sure you maintain adequate thigh clearance. If your armrests get in the way and are not adjustable, consider having them removed.
People work more naturally when the keyboard and input device are at approximately elbow height.
Install an articulating keyboard tray. Obtain a wrist rest. If the arms of your chair are too high to permit a neutral posture, adjust or remove them. Adjustable Keyboard Tray Wrist Rests Reflections and glare make it harder to see the characters on your screen and contribute to eyestrain and headaches. Additionally, in order to avoid the glare, you might move into awkward postures that contribute to neck, back and arm discomfort.