Sit upright in a chair with your hands relaxed by your sides.
Bend your elbow to 90 degrees.
Have an assistant support your weaker arm at the wrist and at your upper arm.
Keeping your elbow bent, slowly lift your weaker arm up, straightening it as you reach towards the ceiling.
The assistant should help support some of the weight of your arm.
Hold this position before returning your arm back down to your side.
Ensure you do not hunch your shoulder during this exercise.
