Steroid injections into joints are usually intended to reduce pain and inflammation. Because the solution injected contains a numbing agent as well as the steroid antiinflammatory, results are fairly rapid. If all goes well, you should expect to experience benefits in the first few days to weeks.
Results may depend on accuracy of the injection. Studies show that physicians who rely on their palpatory skills (vision and touch) have much lower accuracy (and poorer results). Using ultrasound or X-ray imaging to guide the needle improve accuracy from 33 to 93 per cent.
Along with improved accuracy comes rapid improvement of symptoms. Patients with serious limitations in shoulder movement and function appreciate those kind of rapid results when it comes to quality of life issues such as getting dressed, getting back to work, and even being able to wipe the bottom after toileting.
You may be given a series of exercises to perform each day at home. Bending forward and dangling the arm (Codman exercises), stretches, and wall climbing exercises (using the fingers to walk up the wall) can help restore full joint motion and function.