Answer:
Your arms should be comfortable at your side, forming a 45° angle with your upper arms, and your forearms should be parallel to the floor.
Position the keyboard directly in front and close to you so you don't have an excessive reach.
If you are working for a long period of time, alternate between sitting and standing. Take breaks to stretch.
Keep your shoulders, arms, hands and fingers relaxed.
Position your wrists straight or in neutral position while typing.
Adjust your chair height and position so your feet rest flat on the floor, or add a footrest to compensate for a higher chair.
Adjust the keyboard height so that your shoulders can relax and your arms are straight in front of you.