Mary, I know exactly what you mean about shoulder pain. I began losing strength in my left arm about two years ago, but at that time I just chalked it up to old age -- I'm 63 now. I noticed that the muscles in my arm were sometimes as hard and as round as a baseball but but they didn't hurt. Then last summer I started noticing that my shoulder pained me, especially at night. I tried massage, Tylenol, rice bags that I heated and around my shoulder. I tried acupuncture, physical therapy, occupational therapy, and none solved the problem for more than a few hours or a few days.
In Septmber, I went to Mayo Clinic and got the DX of ALS. The doctor there explained to me that the reason my shoulder was hurting was that the weight of my arm, which was hanging limply at my side all day, was pulling my arm out of the socket. The muscles that wrapped around from my shoulder blade had atrophied and it was the tendons that were being abused in an effort to hold my arm where it belonged. He suggested that I wear a sling during the day to hold my arm in place and continue to use the hot rice pack when I napped or retired for the night. Once the muscle stopped atrophying the pain went away.
I still use the sling on occasion, but infrequently. I continue to have a good grip in my left hand the only problem is getting the hand lifted to this spot that I went to grip.
Hope this helps give you an idea of what to do to relieve the pain. Please don't hesitate to contact me if I came to be a further assistance. I am losing the use of my right arm at the moment and am facing a new challenge -- not one that I ever expected I would have to face. But there is some good to come out of this illness, I have had the opportunity to meet so many strong, happy, witty And caring people in the forum. They have become like family. Welcome to our family.