Hi DJ,
Is your husband getting PT for his shoulder and neck? If not, he should. You are not supposed to lift anything that weighs more than a lb for the first couple of weeks after the surgery. Sounds like your husbnd may have been over doing it and has now gotten his shoulder misaligned. You don't want to put any more drag on that side than necessary. I used to put a pillow under my arm when I sat on the sofa to lessen the drag. Likewise in bed to elevate it if I slept on my other side. If he sits at a desk, make certain the cahir has arms. I had no pain with either neck dissection other than what was caused by getting my shoulder misaligned (winged scapula) which resulted in severe back pain.

Have him take it easy for a few weeks and find a good PT.

Take care,
Eileen