standing overhead elbow flexion with opposite hand applying gentle overpressure to increase posterior shoulder and triceps stretch
Stand, elevate the arm overhead and bend the elbow such that fingers touches the shoulder. Place other hand on the elbow, using other hand pull the arm in same direction. Feel for the stretch in underarm, release the pull to starting position. Repeat
Nothing here is a prescription. Your physiotherapist decides which of these are yours, and when.
