Ergoanswers : Elbow & Forearm

An improperly positioned keyboard or mouse will decrease the likelihood of having your wrist in a neutral position. This can lead to overuse of your forearm muscles.
Keyboard/Mouse Height: Adjust the height of your keyboard so that, while typing, your shoulders are relaxed, wrists are flat, and elbows are bent to 90 degrees and resting at your sides (i.e., neutral).
If you can't adjust your keyboard height, raise your chair height, and get a footrest to properly support your legs.
Arm-Rests Too High
When armrests are positioned so that elbows must rest on them, arm movement during typing is reduced, and wrist movement is increased. This increased wrist movement increases the strain on the forearm muscles.
Armrest Position: Adjust armrests 1-2" below elbows, when elbows are at right angles. (Elbows should not bear weight on armrests while typing).
Backrest Position: Adjust lumbar support to fit comfortably in the small low back arch (a small rolled up towel may provide additional support).
Resting your arms or wrists on arm or wrist rests while typing requires forearm muscles to do most of the work. Instead, stronger shoulder and arm muscles should be used to "float" the hands over the keys.
Pulling your fingers upward ("extension") puts a constant strain on the forearm muscles that hold the wrist in extension, and may irritate the tendons on the top of your elbow causing pain in the forearm.
Bending your wrist downward ("flexion") also puts a constant strain on the forearm muscles that hold the wrist in flexion. Additionally, this "flexed" position may irritate the tendons on the bottom of your elbow.
STEP 3) Use your left hand to mildly stretch the right wrist further; slowly rotate right fingers to point away from your body; a mild comfortable stretch should be felt through the top of your forearm
STEP 4) Hold 10 seconds
STEP 5) Switch sides
Wrist Flexor Stretch
STEP 1) Straighten your left arm out in front of you
STEP 2) Bend your wrist backwards, point your fingers up
STEP 3) Use your right hand to mildly stretch the bending wrist further; a mild, comfortable stretch should be felt through the bottom of your forearm
STEP 4) Hold 10 seconds
STEP 5) Switch sides
Prayer Stretch
STEP 1) Place your fingertips together in a prayer position (no other part of your hand should touch)
STEP 2) Slowly move hands down from eye level to chest level; slowly rotate fingers to point towards your chest; a mild, comfortable stretch should be felt through your fingers, hands and wrist