Shoulder external rotation in abduction in supine with band (Shoulder external rotation strengthening, with band, arm out to side 90/90, supine)

Lie on your back and place an elastic band around your foot.
Bend your knee, and turn your shoulder outwards at about 90 degrees, with the elbow in a 90 degree angle.
Keep your wrist in a neutral position.
Extend your knee and slowly rotate your forearm back as far as possible, resisting the movement.
Bend the knee and bring your shoulder back up.
Repeat the exercise.