I'm glad to help cos I'm in a similar situation. Shoulder injuries are the most common bodybuilding injury. One of the best things for older people like myself (41 y.o.) and you to do is to go to a chiropractor every so often--I think every 1-2 months, but I'm not sure. The chiropractor will put the body in balance. The medical/pharmaceutical community wants to prescribe medication and make lots of money. Chiropractor's should charge only $35-$50 for an adjustment. The intial/consultation visit will be a little higher cos some chiropractors take x-rays. Chiro's use electro-stimulation to relax your neck, your lower back, your traps, your shoulders. They stretch out the bod and then push it back into alignment. I highly recommend not only an NT, but a chiropractor--cos a chiro is all-inclusive--the entire bod. Physical therapy is only body-specific and is not as thorough on the whole body as a chiropractor is. Plus, ask your chiro (after u get a referral for a chiro from your fam doctor) about a cutting edge treatment called "Laser." This is a little expensive, but excuse the pun--it's ultra-sound on steroids

x times better!
get yourself also a McDavid hot/cold gel pack shoulder strap pad about $40 on amazon.com. WARM UP WITH A HOT GEL PACK BEFORE TRAINING AND like my physical therapist recommends put ice on the shoulder after working out cos it helps with healing. I thought ice was only immediately after an injury, but it also is a big step in speeding up recuperation and healing muscle fiber tears post-workout.
also "Treat Your Own Rotator Cuff" by Jim Johnson, PT (physical therapist) can also be purchased on amazon.com. There are like 500 reviews with at least a 4 star rating on this book. I have it myself. You will learn about your rotator cuff, its function and also what exercises to do prior to training, during training and how to add strength and HEALING WARMTH to this weak part of the bod--the rotator cuff of the shoulder joint.
finally, when you are doing flat bench presses don't do full range of motion don't bring the bar all the way down to your chest. Also don't completely lock-out. When you were younger you could do full range of motion for a better stretch, but it's a real strain on the little rotator cuff joint when your older.
also when you do upright rows you know how you bring the bar down and kind of let it hang at the bottom of the movement? Don't do that anymore. That's a big strain on the rotator cuff, too. You don't want to hang anymore even though it seems kind of natural. Like also when you do dumbell shoulder shrugs at the bottom, there's a tendency to let that dumbell hang and pull & (maybe rest) before bringing it back up to your ear, BUT *that really stresses the rotator cuff joint in the shoulder--don't do that.
I'm grateful to have helped you in a small way cos like I said shoulder probs are a very common bodybuilding injury--the rotator cuff is an INHERENTLY tiny, weak part of the body, and I'm happy to help because I myself also want to repair my own shoulder problems and to prevent further.
The mind is your best tool..mind over matter!...you can and WILL get your shoulder as close to 100% better!
Take care, and let us know of your progress at another post.
