I was diagnosis with osteoarthritis in the right knee 2yrs ago and now I have a lower lumber sprain in my back on the right side is this related to my knee pain.

Often it might be, yes, because you favor one leg and walk off balance.
Other than that, no. Osteoarthritis is just plain old arthritis, and most of us have it all over our bodies by the time we hit our 60s. I can't even find a position to sleep that doesn't hurt anymore. A sprain needs a warm bath or long shower, massage, maybe an Icy Hot or other large patch, a heating pad with a damp washcloth between you and it, and some gentle bending exercise.