Stiff and painful are very common and are often correlated with painful and stiff necks.
Our chiropractor Lena from Milton Chiropractic Clinic demonstrates a really gentle, low key exercise that can improve the shoulder mobility dramatically.
One does need an elastic band for this exercise, commonly known as a “Teraband” which are widely available on Amazon or in our clinic.
We would recommend to perform this exercise at least twice a day.