Passive shoulder flexion to 90degrees arm in a sling (Shoulder flexion to 90° PROM, arm in sling, supine; 01)

Lie down on your back on a mat or bed.
Relax your affected arm in the sling and cradle it in your other arm.
Using the effort of your good arm, lift your affected arm up and forwards to shoulder height and then slowly lower it back down.
Do not use your affected arm to generate the movement, use your good arm and do not hunch your shoulders up.
Relax and repeat.