Hiya... This is what I'd recommend: 1. Get shoulders joint / girdle / rotator cuff examined for stiffness, rigidity, pain and mobility. Learn yourself as well. 2. Use a resistance band or tube for improving mobility 3. Focus on isometric contractions, in all planes possible If in doubt, employee the services of a physiotherapist but I'd suggest you learn the moves yourself and design a program. If mobility is fine and only muscle weakness present, you should be good to go as far as gym id concerned. But, again... someone's who's examined you directly will be better judge.

physiothrapy center for specific shoulder exercise

You can start slowly with simple exercises like aerobics. And as you build power , you can resume exercises as well.