How long does a rota cuff injury take to heal. i have damaged all 4 muscles it is 7 weeks now and still very painfull. i also have arthritis and fibro?

Depends: It depends on what happened. If you have torn all 4 muscles and have had surgery, that is a huge surgery. It can take up to a year to recover -- if ever. If you have had a strain to the muscles tendons, it can take up to 3 months. The arthritis makes it tough because it makes it hard to regain your motion. I don't know if fibro is fibromyalgia or fibrosis -- if fibrosis that is scarring.

Healing: Sounds like you have a massive rotator cuff tear, which takes a very long time to heal (if fixed), if ever. There are sometimes a lot of tension on the cuff that can leadsto retears. There is quite a continuum of rtc pathology, but if it does heal, the tendon to bone healing can take up to 3 months. 9 months to a year is what you can expect to make a full recovery.