The respiratory system is affected by the ALS. The intercostal muscles and the diaphragm usually get affected when the arms/shoulders are affected by the ALS. That is why some of the PALS opt for the non-invasive positive pressure ventilation like the BIPAP or get a tracheotomy and a ventilator.
Below are links to 5 separate slide educational presentations on the respiratory system and problems/symptoms /treatments in neuromuscular and spices cord injuries. The unit 3 one is the one on breath stacking and another name for it is lung volume recruitment exercises.
If you follow the slides they should help you understand what is happening to your PALS and anticipate what to do next and understand what the doctor orders.
Patsy, You are a saint to have posted these sites. What a refresher course for me and how well-explained and well-organized for the lay person. I will definitely be referring back to this excellent site as my husband's ALS progresses. Thanks a million.
Many blessings and all the best,