
push against wall with straight elbows while protracting scapulae, pillow between hands and wall for resistance
stand facing the wall, raise the arms to 90 degree and rest the hands on the wall keeping the elbow straight, place one pillow between the hand and wall. Push the wall, try to round the shoulders and hold. Release the push and back to starting position and repeat.
Nothing here is a prescription. Your physiotherapist decides which of these are yours, and when.