These are isometric exercises. That means you contract your muscles without actually moving.

• Push forward (flex): Stand facing a wall or doorjamb, about 15 cm (6 in.) or less back. Hold your affected arm against your body. Make a closed fist with your thumb on top and gently push your hand forward into the wall with about 25% to 50% of your strength. Don't let your body move backward as you push. Hold for 5 seconds. Repeat 8 to 12 times.
• Push backward (extend): Stand with your back flat against a wall. Your upper arm should be against the wall, with your elbow bent 90 degrees (your hand straight ahead). Push your elbow gently back against the wall with about 25% to 50% of your strength. Don't let your body move forward as you push. Hold for 5 seconds. Repeat 8 to 12 times.