I Have A Question For My Mom. She Has Been

I have a question for my mom. She has been having pain in both her shoulders or near them(around that area). She can only lift her arms about 60 degrees sideways, 90 degrees forwards, and about 30 degrees backwards. Beyond that point, it hurts her really bad. She's been to the doctor and they said there's nothing wrong with her shoulder. She's also in her forty's and has diabetes. I am wondering if anyone could help with treatment advice, medicines of any kind, or anything that I could do. Please help, I just want her to be herself without the pain.