Hello Dobgima, welcome to a fellow professional from Cameroon! It is wonderful to think that this portal has such global reach.
You are right that back pain can often be managed through proper exercises. Of course, every person is unique, and disc degeneration may not be the cause for the pain. There are many other ways to hurt your back, and only a physician can diagnose that. I personally also believe that getting older alone is not an automatic cause for back problems.
Having said all that, there are some generic exercises often recommended for the maintenance of back health, and I have traced three documents which will hopefully give you a starting point.
I wish you the best of health.
Planks Front and side planks are safe and effective for both a strong back and abdominals. Here are a couple of variations of this exercise from the begginer to the more advance.