Stand up straight facing a wall.
Wrap a band around both forearms, just above your wrists.
Place your elbows and forearms on the wall, shoulder width apart.
There should be some tension in the band.
Your forearms should be vertical with your hands pointing up to the ceiling.
Ensure you keep a straight line from your head to your heels.
Gently press your forearms into the wall, flattening your shoulder blades against your ribs.
Do not hunch your shoulders up, or round your upper back.
Keeping this control with your shoulder blades, slide your forearms up and down the wall.
Ensure your forearms do not drop in towards each other.
The key to this exercise is to ensure your shoulder blades remain tight against your rib cage, and your forearms remain parallel throughout.