Hi I would agree with Robert, try reducing the intensity and give the patient an increased awareness of thier scapula position.

However, if he has no symptoms you might experience problems as he has adapted to this position and even though it is not 'ideal' it is functional for him. Most physios treat this problem in the presence of pain so its easy to justify changing the position (I remember changing a students shoulder position once as the head of humerus was too forward-she experienced pain in this new position even though it was anatomically better!).

Hallamshire Physiotherapy