The back pain is commonly caused by the following reasons: 1. It may be caused by the strain on the muscles of the back due to the long-term need to walk with the back up in the late stages of pregnancy. 2. It may be caused by fasciitis of the back, a sterile inflammation of the fascia on the surface of the back muscles. 3. The pain is generally more painful when pressed, and the pain point is clearer. 4. It may be caused by degenerative changes in the cervical spine, such as intervertebral discs, osteophytes or small joint misalignments, which compress the nerve roots in the back of the shoulder and cause nerve pulling pain in the back of the shoulder.