Pain in shoulder that runs into back of arm when moving or sitting slouched. i have a slipped disk in my lower back is this from it?

Not likely. : Disc problems in the low back can cause irritation of the lumbar nerves leading to pain, tingling, numbness, in the legs. The nerves that go to the arms start out in the neck (cervical spine). Pain from the shoulder going down the arm can be a number of things including pinched nerves in the neck or near the shoulder, muscle problems, or problems in the shoulder itself.

Muscles: Generally disc problems in the lower back dont cause shoulder related pain but muscles can. What you need to do is start pt and talk to your pcp.