Lie on your back holding a stick across your body in each hand.
Bend your elbows so that the stick lies across your chest.
Your arms should be around shoulder width apart, or slightly wider depending on what is comfortable.
Using your unaffected hand to assist the movement, lift the stick directly up into the air above your chest.
Your elbows should straighten.
Control the movement as you slowly lower your arms back down again, and repeat.