Resisted GHjt flexion into ER(90) (Shoulder flexion to 180° strengthening, with band, into shoulder external rotation 90/90, standing)

Stand up straight with a resistance band looped around a stable object.
Hold the ends in each hands.
Keeping your body straight and shoulders relaxed, move your arms forwards and up towards the ceiling.
Next, bend your elbows out to the side until you have a right angle at your elbows.
Your hands should be in line with the top of your head.
Control the movement as you bring your arms back up towards the ceiling and then return to the starting position.