Many chronic shoulder injuries that people have suffered through for months and sometimes up to years can have other areas in the body that may be influencing these injured areas.
The shoulder in its own right is a very complex joint.
When simplified the shoulder is a ball and socket joint of which also consists of muscles, ligaments, tendons, and bones. Most shoulder pain originates from injury to the soft tissues of the shoulder, but in some cases, especially when you experience both neck and shoulder pain, cervical disk disease or a problem with the bones or nerves in your neck may be the source of your problem. In other cases poor biomechanics involving the scapula (shoulder blade) can put undue strain on the rotator cuff muscles, tendons and ligaments. Furthermore, the thoracic spine (middle back) and chest muscles can influence how a shoulder moves and more so can interfere with the healing process.
Exercises that focus on strengthening the scapula to provide a stable attachment site for the rotator cuff muscles will help reduce pain felt in the shoulder joint. As well as mobilizations of the cervical and thoracic vertebrae will also influence how the nerves and muscles that control the shoulder blade will interact with each other.
Many acute and chronic shoulder injuries would benefit from a thorough physiotherapy assessment of the shoulder but also the other joints that influence the shoulder.